CI-unixish

updated `actions/checkout` to `v6` #1258

Sign in to view logs

Run time

Learn about OS pricing on GitHub Actions

Job	Run time
build (ubuntu-22.04, clang++)	53s
build (ubuntu-22.04, g++)	39s
build (ubuntu-24.04, clang++)	13m 23s
build (macos-15, clang++)	40s
build (macos-26, clang++)	1m 32s
build (macos-15-intel, clang++)	1m 16s
build (macos-14, clang++)	56s
build (ubuntu-24.04, g++)	3m 2s
	22m 21s