RFR: 8366369: Add @requires linux for GTK L&F tests

[Alexey Ivanov]

On Sat, 30 Aug 2025 03:36:51 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

> > The purpose of this PR is to avoid running GTK L&F specific tests on the platforms where GTK L&F isn't available.
> 
> But why not try loading it? That would help verify that the validation for missing dependencies works correctly. I think the patch is based on assumptions that are not necessarily true:

Both assumptions are true:

> * GTK L&F cannot be supported on platforms other than Linux

If I run the test on Windows or on macOS, I get ` java.lang.ClassNotFoundException: com.sun.java.swing.plaf.gtk.GTKLookAndFeel`.

GTK L&F may be supported on other platforms but *it is not*.

> * headful systems always have the GTK library installed

Since GNOME is the only desktop environment officially supported, there's no way GTK library isn't installed on a correctly configured headful host. If GTK library isn't available, it needs installing.

This is why I think these tests have to fail if `GTKLookAndFeel` can't be loaded rather than silently ignore the failure… even on Linux hosts.

Thus, I'm standing with my intent: I see no point in even trying to start a GTK L&F test on platforms other than Linux.

I did run the updated tests on CI, and the tests pass.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26995#discussion_r2314034678