build

tests: fix flakiness in shallow Git repo test #15848

Job	Run time
build (ubuntu-latest)	4m 43s
Build jj-lib without Git support	47s
build (macos-13)	6m 27s
cargo-deny (advisories)	21s
build (macos-14)	3m 49s
cargo-deny (bans licenses sources)	28s
Check protos	23s
build (windows-latest)	9m 49s
build (ubuntu-latest, --all-features)	5m 49s
Clippy check	2m 30s
Check that MkDocs can build the docs	22s
Check that MkDocs can build the docs with Poetry 1.8	21s
Check formatting	17s
	36m 6s

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