Use macOS 11 / Xcode 12.4 for GitHub actions runs. As noted in the JBS bug, macOS 10.15 has been deprecated as a GitHub Actions platform, and will be removed completely on August 30th. See https://github.com/actions/virtual-environments#available-environments and actions/virtual-environments#5583 for context.
This PR also switches to using XCode 12.4, which matches our production builds. As you can see from the GHA run, the tests pass after this change. ------------- Commit messages: - 8290527: Bump macOS GitHub actions to macOS 11 Changes: https://git.openjdk.org/jfx/pull/844/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=844&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8290527 Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod Patch: https://git.openjdk.org/jfx/pull/844.diff Fetch: git fetch https://git.openjdk.org/jfx pull/844/head:pull/844 PR: https://git.openjdk.org/jfx/pull/844
