Add support for adding `setup-dotnet` steps to `sync.sh` #6320

Job	Run time
Ruby analysis (macos-latest, linked)	1m 0s
Ruby analysis (ubuntu-latest, nightly-latest)	45s
Ruby analysis (ubuntu-latest, default)	52s
Ruby analysis (macos-latest, default)	55s
Ruby analysis (ubuntu-latest, linked)	43s
Ruby analysis (macos-latest, nightly-latest)	1m 39s
	5m 54s

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