Update which requirement from 6.0.3 to 7.0.0 (#875)

Updates the requirements on [which](https://github.com/harryfei/which-rs) to permit the latest version.
- [Release notes](https://github.com/harryfei/which-rs/releases)
- [Changelog](https://github.com/harryfei/which-rs/blob/master/CHANGELOG.md)
- [Commits](harryfei/which-rs@6.0.3...7.0.0)

---
updated-dependencies:
- dependency-name: which
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

libcnb-package/Cargo.toml

@@ -23,4 +23,4 @@ libcnb-data.workspace = true
 petgraph = { version = "0.6.5", default-features = false }
 thiserror = "1.0.65"
 uriparse = "0.6.4"
-which = "6.0.3"
+which = "7.0.0"