This seems to happen more often now, but interestingly it only seems to happen on Linux. The last run was in https://github.com/mozilla/pdf.js/pull/13021#issuecomment-786012076. @calixteman Could you take a look at this to see if we can make the tests pass again?

The relevant log output is:

```
Failures:
1) Interaction in js-colors.pdf must changes colors
  Message:
[31m    In firefox: Expected 'rgba(0, 54, 255, 0.13)' to equal 'rgb(255, 0, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgba(0, 54, 255, 0.13)' to equal 'rgb(255, 0, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:661:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:667:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:676:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:661:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:667:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:676:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:661:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:667:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:676:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 0, 255)' to equal 'rgb(255, 0, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:661:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(255, 0, 0)' to equal 'rgb(0, 255, 0)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:667:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
  Message:
[31m    In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.[0m
  Stack:
    Error: In firefox: Expected 'rgb(0, 255, 0)' to equal 'rgb(0, 0, 255)'.
        at <Jasmine>
        at Promise.all.pages.map (/home/ubuntu/pdfjs/botio-files-pdfjs/private/e2b7f68c964756b/test/integration/scripting_spec.js:676:16)
        at process._tickCallback (internal/process/next_tick.js:68:7)
```
it("must show a text field and then make in invisible when content is removed", async () => {
      await Promise.all(
        pages.map(async ([browserName, page]) => {
          let visibility = await page.$eval(
            "#\\34 27R",
            el => getComputedStyle(el).visibility
          );
          expect(visibility).withContext(`In ${browserName}`).toEqual("hidden");
          await page.type("#\\34 16R", "3.14159", { delay: 200 });
          await page.click("#\\34 19R");
          visibility = await page.$eval(
            "#\\34 27R",
            el => getComputedStyle(el).visibility
          );
          expect(visibility)
            .withContext(`In ${browserName}`)
            .toEqual("visible");
          
          await clearInput(page, "#\\34 16R");
          
          await page.click("#\\34 19R");
          visibility = await page.$eval(
            "#\\34 27R",
            el => getComputedStyle(el).visibility
          );
          expect(visibility).withContext(`In ${browserName}`).toEqual("hidden");
        })
      );
    });
    it("must format the field with 2 digits and leave field with a click", async () => {