[Build] Replace use of coactions/setup-xvfb

[HannesWell]

Similar to eclipse-equinox/equinox#677.

[github-actions]

Test Results

   482 files   -     4     482 suites   - 4   7m 19s ⏱️ - 1m 45s
 4 105 tests  -    54     166 ✅  - 3 985   2 💤  -  6  0 ❌ ±0  3 937 🔥 +3 937 
20 068 runs  +3 678  12 296 ✅  - 4 002  82 💤  - 10  2 ❌ +2  7 688 🔥 +7 688 

For more details on these errors, see this check.

Results for commit 37d346a. ± Comparison against base commit 8c39dcd.

This pull request removes 54 tests.

org.eclipse.swt.graphics.ImageWin32Tests ‑ testImageShouldHaveDimesionAsPerZoomLevel
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicASCII_dollarSign
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicASCII_emptyString
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicASCII_letterA
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicASCII_letters
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16LE_null
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16_AsciiLetters
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16_Asciiletter
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16_LotsOfLetters
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16_letter
…

♻️ This comment has been updated with latest results.

[HannesWell]

The tests fail on Linux although XVFB is now available by default on the Linux runners:
https://github.com/actions/runner-images/blob/ubuntu22/20240922.1/images/ubuntu/Ubuntu2204-Readme.md