Remove WS_CARBON check

[elsazac]

This PR removes the only remaining WS_CARBON check from the codebase.The Carbon backend is no longer used or supported in SWT, as all modern macOS environments use the Cocoa backend (WS_COCOA). This check is now obsolete and can be removed. (#2964)

[github-actions]

Test Results

 2 778 files  ±0   2 778 suites  ±0   1h 42m 47s ⏱️ + 3m 17s
 7 932 tests ±0   7 704 ✅ ±0  228 💤 ±0  0 ❌ ±0 
23 351 runs  ±0  22 605 ✅ ±0  746 💤 ±0  0 ❌ ±0 

Results for commit b060d75. ± Comparison against base commit 634e5f0.

♻️ This comment has been updated with latest results.

[vogella]

Thanks @elsazac

[mickaelistria]

This is causing #3141 and should probably be reverted (one may add a line to log warning when using 'carbon' instead of 'cocoa') as it seems clear that the ecosystem, and even Platform, is not ready for dropping this legacy definition.

[basilevs]

even Platform

eclipse.platform.ui/bundles/org.eclipse.ui/plugin.xml

Lines 236 to 240 in 5922d0c

	<key
	platform="carbon"
	commandId="org.eclipse.ui.navigate.backwardHistory"
	sequence="COMMAND+["
	schemeId="org.eclipse.ui.defaultAcceleratorConfiguration" />

I was hit by this problem when working in PDE and confirmed it also breaks navigation across simple text editors, so Platform was very much broken.

At the very least, Platform's plugin.xml files should be updated when this change is applied.

[mickaelistria]

@basilevs if you have the opportunity to submit PRs replacing those carbon by cocoa in platform, that would be very welcome!

[elsazac]

if you have the opportunity to submit PRs replacing those carbon by cocoa in platform, that would be very welcome!

@mickaelistria I would like to work on this again, but I wanted to understand , when we replace carbon with cocoa and remove the code containing WS_CARBON, that change will now honour the bindings used in all the plugins across Eclipse. But, would this change affect any third-party plugins that might still rely on carbon?