build(deps): bump once_cell from 1.20.3 to 1.21.0

Bumps [once_cell](https://github.com/matklad/once_cell) from 1.20.3 to 1.21.0.
- [Changelog](https://github.com/matklad/once_cell/blob/master/CHANGELOG.md)
- [Commits](matklad/once_cell@v1.20.3...v1.21.0)

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

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

Author: dependabot[bot]

Cargo.lock

@@ -38,7 +38,7 @@ itertools = "0.14.0"
 hickory-resolver = { version = "0.24.3", features = ["dns-over-rustls"] }
 anyhow = "1.0.40"
 text_placeholder = { version = "0.5", features = ["struct_context"] }
-once_cell = "1.20.3"
+once_cell = "1.21.0"
 
 [dev-dependencies]
 parameterized = "2.0.0"