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Add `FileSystem` abstraction for testing #11354

Job	Run time
Split workflow (ubuntu-latest, default)	1m 6s
Split workflow (ubuntu-latest, linked)	1m 23s
Split workflow (macos-latest, linked)	2m 19s
Split workflow (ubuntu-latest, nightly-latest)	1m 12s
Split workflow (macos-latest, default)	2m 7s
Split workflow (macos-latest, nightly-latest)	2m 19s
	10m 26s