Add workflow to run with GTK4 enabled

[laeubi]

Currently everything is run with GTK3 by default but we can't tell the current state of affairs with GTK4.

This now adds a new action that run the build (and tests) with GTK4 enabled.

[github-actions]

Test Results

   484 files  +  101     484 suites  +101   6m 24s ⏱️ +30s
 4 081 tests  -   206   4 074 ✅  -   201   7 💤  - 5  0 ❌ ±0 
15 993 runs  +3 650  15 901 ✅ +3 653  92 💤  - 3  0 ❌ ±0 

Results for commit 3944068. ± Comparison against base commit f37c155.

This pull request removes 225 and adds 19 tests. Note that renamed tests count towards both.

org.eclipse.swt.graphics.ImageWin32Tests ‑ testImageShouldHaveDimesionAsPerZoomLevel
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_afterPageReload[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_String[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_boolean[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_integer[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_javaReturningInt[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_javaReturningString[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_callback_with_multipleValues[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_BrowserFunction_multiprocess[browser flags: 524,288]
…

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
org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_HeuristicUTF16_letters
…

This pull request removes 7 skipped tests and adds 1 skipped test. Note that renamed tests count towards both.

org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_ClearAllSessionCookies[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_TabTraversalOutOfBrowser[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_get_set_Cookies[browser flags: 524,288]
org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_setForegroundAlphaLorg_eclipse_swt_graphics_Color[browser flags: 524,288]
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_events_KeyEvent ‑ testEnglishUs_multipleLetters
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_events_KeyEvent ‑ testEnglishUs_unorderedCtrlC
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_events_KeyEvent ‑ testEnglishUs_unpairedKeyUp

org.eclipse.swt.tests.gtk.Test_GtkConverter ‑ test_Heuristic_specialSingleCases

This pull request skips 1 test.

org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser ‑ test_Constructor_multipleInstantiationsInDifferentThreads[browser flags: 0]

♻️ This comment has been updated with latest results.