build: bump once_cell from 1.20.2 to 1.20.3

Bumps [once_cell](https://github.com/matklad/once_cell) from 1.20.2 to 1.20.3.
- [Changelog](https://github.com/matklad/once_cell/blob/master/CHANGELOG.md)
- [Commits](matklad/once_cell@v1.20.2...v1.20.3)

---
updated-dependencies:
- dependency-name: once_cell
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.lock

@@ -80,7 +80,7 @@ lazy_static = "1.5.0"
 lib = { package = "git-branchless-lib", version = "0.10.0", path = "git-branchless-lib" }
 man = "0.3.0"
 num_cpus = "1.16.0"
-once_cell = "1.19.0"
+once_cell = "1.20.3"
 path-slash = "0.2.1"
 portable-pty = "0.8.1"
 rayon = "1.10.0"