RFR: 8169285: Re-enable javafx.swt tests [v3]

[Marius Hanl]

> With this change, you can now run the `swt` tests as easy as: `:swt:test -PSWT_TEST=true`.
> ![image](https://github.com/user-attachments/assets/928141b5-ac81-4b15-9d86-5ea87f47c1c4)
> 
> Note: At one point `IS_FULL_TEST` was used as well for the enablement of the tests. I don't see any reason for it, and one flag seems to be enough to me. But open for opinions on this one.

Marius Hanl has updated the pull request incrementally with one additional commit since the last revision:

  SWT_TEST default is false on MacOS

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1783/files
  - new: https://git.openjdk.org/jfx/pull/1783/files/a99f75ae..eabc48a2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1783&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1783&range=01-02

  Stats: 6 lines in 1 file changed: 0 ins; 5 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1783.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1783/head:pull/1783

PR: https://git.openjdk.org/jfx/pull/1783