Alternate title: _Applying #6684-similar fix to stroke_
#6684 makes sure the "current" transformation, at the moment of filling radial gradients is the `baseTransform` (that of the rescource (page), as it says in the specs). However, this should also be fixed in [`CanvasGraphics_stroke`](https://github.com/dsprenkels/pdf.js/blob/a9081653fc565eb72c3eb5142c17088cb162e7ce/src/display/canvas.js#L1052).

(-4 * coords[ps[0]][1] -
          coords[ps[15]][1] +
          6 * (coords[ps[4]][1] + coords[ps[1]][1]) -
          2 * (coords[ps[12]][1] + coords[ps[3]][1]) +
          3 * (coords[ps[13]][1] + coords[ps[7]][1])) /
          9,
      ]);
      ps[6] = coords.length;
      coords.push([
        (-4 * coords[ps[3]][0] -
          coords[ps[12]][0] +
          6 * (coords[ps[2]][0] + coords[ps[7]][0]) -
          2 * (coords[ps[0]][0] + coords[ps[15]][0]) +
          3 * (coords[ps[4]][0] + coords[ps[14]][0])) /
          9,
        (-4 * coords[ps[3]][1] -
          coords[ps[12]][1] +
          6 * (coords[ps[2]][1] + coords[ps[7]][1]) -
          2 * (coords[ps[0]][1] + coords[ps[15]][1]) +
          3 * (coords[ps[4]][1] + coords[ps[14]][1])) /
          9,
      ]);
      ps[9] = coords.length;
      coords.push([
        (-4 * coords[ps[12]][0] -
          coords[ps[3]][0] +
          6 * (coords[ps[8]][0] + coords[ps[13]][0]) -
          2 * (coords[ps[0]][0] + coords[ps[15]][0]) +
          3 * (coords[ps[11]][0] + coords[ps[1]][0])) /
          9,