Bump bufbuild/buf-setup-action in /.github/util/initialize (#2328)

Bumps [bufbuild/buf-setup-action](https://github.com/bufbuild/buf-setup-action) from 1.38.0 to 1.39.0.
- [Release notes](https://github.com/bufbuild/buf-setup-action/releases)
- [Commits](bufbuild/buf-setup-action@v1.38.0...v1.39.0)

---
updated-dependencies:
- dependency-name: bufbuild/buf-setup-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/util/initialize/action.yml

@@ -31,7 +31,7 @@ runs:
     - run: npm install
       shell: ${{ runner.os == 'Windows' && 'powershell' || 'bash' }}
 
-    - uses: bufbuild/buf-setup-action@v1.38.0
+    - uses: bufbuild/buf-setup-action@v1.39.0
       with: {github_token: "${{ inputs.github-token }}"}
 
     # This composite action requires bash, but bash is not available on windows-arm64 runner.