Bump the libcnb group across 1 directory with 3 updates

Bumps the libcnb group with 3 updates in the / directory: [libcnb](https://github.com/heroku/libcnb.rs), [libherokubuildpack](https://github.com/heroku/libcnb.rs) and [libcnb-test](https://github.com/heroku/libcnb.rs).


Updates `libcnb` from 0.21.0 to 0.22.0
- [Release notes](https://github.com/heroku/libcnb.rs/releases)
- [Changelog](https://github.com/heroku/libcnb.rs/blob/main/CHANGELOG.md)
- [Commits](heroku/libcnb.rs@v0.21.0...v0.22.0)

Updates `libherokubuildpack` from 0.21.0 to 0.23.0
- [Release notes](https://github.com/heroku/libcnb.rs/releases)
- [Changelog](https://github.com/heroku/libcnb.rs/blob/main/CHANGELOG.md)
- [Commits](heroku/libcnb.rs@v0.21.0...v0.23.0)

Updates `libcnb-test` from 0.21.0 to 0.22.0
- [Release notes](https://github.com/heroku/libcnb.rs/releases)
- [Changelog](https://github.com/heroku/libcnb.rs/blob/main/CHANGELOG.md)
- [Commits](heroku/libcnb.rs@v0.21.0...v0.22.0)

---
updated-dependencies:
- dependency-name: libcnb
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: libcnb
- dependency-name: libherokubuildpack
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: libcnb
- dependency-name: libcnb-test
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: libcnb
...

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

buildpacks/go/Cargo.toml

@@ -13,8 +13,8 @@ hex = "0.4.3"
 flate2 = { version = "1", default-features = false, features = ["zlib"] }
 # libcnb has a much bigger impact on buildpack behaviour than any other dependencies,
 # so it's pinned to an exact version to isolate it from lockfile refreshes.
-libcnb = { version = "=0.21.0", features = ["trace"] }
-libherokubuildpack = { version = "=0.21.0", default-features = false, features = ["log"] }
+libcnb = { version = "=0.22.0", features = ["trace"] }
+libherokubuildpack = { version = "=0.23.0", default-features = false, features = ["log"] }
 semver = "1"
 serde = "1"
 sha2 = "0.10"
@@ -24,5 +24,5 @@ toml = "0.8"
 ureq = { version = "2", features = ["json"] }
 
 [dev-dependencies]
-libcnb-test = "=0.21.0"
+libcnb-test = "=0.22.0"
 tempfile = "3"