RFR: 8321638: Update to SWT 4.30

Wed Jan 3 18:53:09 UTC 2024

This PR updates the version of SWT that we use we use when building and testing the `javafx.swt` modules to 4.30.

NOTE: we do not distribute SWT, but only use it during build and (manual) test.

We currently use SWT 4.6. In addition to being old, this version does not provide macOS / aarch64 binaries, which are needed for testing on that platform.

I've tested this on all platforms.

-------------

Commit messages:
 - 8321638: Update to SWT 4.30

Changes: https://git.openjdk.org/jfx/pull/1315/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1315&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321638
  Stats: 25 lines in 2 files changed: 2 ins; 4 del; 19 mod
  Patch: https://git.openjdk.org/jfx/pull/1315.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1315/head:pull/1315

PR: https://git.openjdk.org/jfx/pull/1315