Update BREE to Java21 for SWT #9048

Job	Run time
Event File	4s
Build (Linux) (21) / build	11m 12s
Build (macOS) (21, cocoa.macosx.x86_64, macos-15-intel) / build	11m 19s
Build (macOS) (21, cocoa.macosx.aarch64, macos-latest) / build	9m 0s
Build (Windows) (21) / build	13m 53s
	45m 28s

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