### CI Link

https://gradle-enterprise.elastic.co/s/323cgxy7itfky

### Repro line

REPRODUCE WITH: ./gradlew ':server:test' --tests "org.elasticsearch.common.StringsTests.testDeleteAny" -Dtests.seed=8A64C9DD086550D3 -Dtests.locale=it -Dtests.timezone=Asia/Baghdad -Druntime.java=17	

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

https://gradle-enterprise.elastic.co/scans/tests?search.timeZoneId=Europe/Rome&tests.container=org.elasticsearch.common.StringsTests&tests.test=testDeleteAny

### Failure excerpt

```
java.lang.AssertionError: |  
  | Expected: "짞ĐGⰣ*ﮢ" |  
  | but: was "짞ĐGⰣﮢ"
```
server/src/test/java/org/elasticsearch/common/StringsTests.java
public void testPadStart() {
        String testStr;
        assertThat(padStart("", 5, 'a'), equalTo("aaaaa"));
        assertThat(padStart(testStr = randomAlphaOfLength(6), 10, ' '), equalTo(" ".repeat(4) + testStr));
        assertThat(padStart(testStr = randomAlphaOfLength(6), 5, ' '), equalTo(testStr));
        assertThat(padStart(testStr = randomAlphaOfLength(6), 10, 'f'), equalTo("f".repeat(4) + testStr));
    }
    public void testToLowercaseAscii() {
        String testStr;
        assertThat(toLowercaseAscii(""), equalTo(""));
        assertThat(toLowercaseAscii(testStr = randomAlphaOfLength(5)), equalTo(testStr.toLowerCase(Locale.ROOT)));
        
        testStr = IntStream.rangeClosed(0, 255).mapToObj(i -> Character.toString((char) i)).collect(Collectors.joining());
        assertThat(toLowercaseAscii(testStr), equalTo(lowercaseAsciiOnly(testStr)));
        
        assertThat(toLowercaseAscii(testStr = randomUnicodeOfCodepointLength(20)), equalTo(lowercaseAsciiOnly(testStr)));
    }
    private static String lowercaseAsciiOnly(String s) {
        
        StringBuilder sb = new StringBuilder(s);
        for (int i = 0; i < sb.length(); i++) {
            char c = sb.charAt(i);
            if (c >= 'A' && c <= 'Z') {
                sb.setCharAt(i, (char) (sb.charAt(i) + 32));
            }
        }
        return sb.toString();
    }
}