Only generate valid names for `FsPath` tests #277

Job	Run time
cabal-check (9.6.4, 3.10.3.0, ubuntu-latest)	2m 17s
cabal-fmt (9.6.4, 3.10.3.0, ubuntu-latest)	2m 53s
build (8.10.7, 3.10.3.0, ubuntu-latest)	2m 9s
stylish-haskell (9.6.4, 3.10.3.0, ubuntu-latest)	2m 36s
build (8.10.7, 3.10.3.0, windows-latest)	4m 34s
build (8.10.7, 3.10.3.0, macOS-13)	3m 35s
build (9.2.8, 3.10.3.0, ubuntu-latest)	2m 4s
build (9.2.8, 3.10.3.0, windows-latest)	3m 40s
build (9.2.8, 3.10.3.0, macOS-13)	4m 1s
build (9.4.8, 3.10.3.0, ubuntu-latest)	2m 52s
build (9.4.8, 3.10.3.0, windows-latest)	4m 34s
build (9.4.8, 3.10.3.0, macOS-13)	8m 11s
build (9.6.4, 3.10.3.0, ubuntu-latest)	2m 46s
build (9.6.4, 3.10.3.0, windows-latest)	6m 3s
build (9.6.4, 3.10.3.0, macOS-13)	6m 42s
build (9.8.2, 3.10.3.0, ubuntu-latest)	1m 7s
build (9.8.2, 3.10.3.0, windows-latest)	3m 52s
build (9.8.2, 3.10.3.0, macOS-13)	7m 18s
	1h 11m 14s

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