build

Implement `jj sign` and `jj unsign` commands #18179

Job	Run time
Build without Git support	1m 15s
build (ubuntu-24.04)	5m 40s
build (macos-13)	8m 59s
build (macos-14)	5m 50s
cargo-deny (advisories)	24s
build (windows-latest)	9m 45s
cargo-deny (bans licenses sources)	22s
build (ubuntu-24.04, --all-features)	6m 45s
Run doctests	2m 40s
Check protos	43s
Clippy check	2m 50s
Check that MkDocs can build the docs	9s
Check formatting	16s
Check that MkDocs can build the docs with latest Python and uv	9s
	45m 47s

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