Bump once_cell from 1.20.2 to 1.20.3 in /rust (#5592)

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](https://github.com/matklad/once_cell/compare/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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

rust/kcl-derive-docs/Cargo.toml

@@ -14,7 +14,7 @@ proc-macro = true
 [dependencies]
 Inflector = "0.11.4"
 convert_case = "0.8.0"
-once_cell = "1.20.2"
+once_cell = "1.20.3"
 proc-macro2 = "1"
 quote = "1"
 regex = "1.11"