fix: Remove click() from CheckboxTester (#2079) (CP: 9.5)

[vaadin-bot]

No description provided.

[mcollovati]

@TatuLund the change cannot be picked as-is because it requires #2012 that in turn cannot be backported as it is a breaking change.

I guess we just need to remove the @Override annotation and add again the click() method implemented as

    public void click() {
        click(0, new MetaKeys());
    }

Same goes for #2081

[TatuLund]

Yes, I noticed it too when CP failed

[github-actions]

Test Results

  154 files  ±0    154 suites  ±0   16m 54s ⏱️ + 1m 42s
1 132 tests ±0  1 126 ✅ ±0  6 💤 ±0  0 ❌ ±0 
1 502 runs  ±0  1 496 ✅ ±0  6 💤 ±0  0 ❌ ±0 

Results for commit b6bfd03. ± Comparison against base commit c2d8793.

♻️ This comment has been updated with latest results.