Add a repository for cargo-lockfile-sync

Author: oli-obk

procedures/crates.md

@@ -168,3 +168,4 @@ This section contains the list of existing out-of-tree, compiler team-maintained
   - [`rust-lang/chalk`](https://github.com/rust-lang/chalk/)
   - [`rust-lang/polonius`](https://github.com/rust-lang/polonius/)
   - [`rust-lang/measureme`](https://github.com/rust-lang/measureme/)
+  - [`rust-lang/cargo-lockfile-sync`](https://github.com/rust-lang/cargo-lockfile-sync/)