feat(ci): publish GitHub release and Homebrew package

This change updates the GitHub Actions workflow to publish the Vespa CLI to both GitHub Releases and Homebrew. The key changes are:

- Publish the GitHub release and capture the release URL
- Only publish to Homebrew if a GitHub release was successful
- Install the CLI package via Homebrew if a release was published

.github/workflows/publish-cli.yml

@@ -151,19 +151,24 @@ jobs:
           brew install --quiet coreutils gh zip go
 
       - name: Publish to GitHub Releases
+        id: github-release
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
           # Release to Github directly, bypassing the diff check as we already perform this check in the "prepare" job.
           make -- --dist-github
+          release_url="$(cat /tmp/vespa-cli-release-url.txt || true)"
+          echo "release-url=${release_url}" > "${GITHUB_OUTPUT}"
 
       - name: Publish to Homebrew
+        if: steps.github-release.outputs.release-url != ''
         env:
           HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.HOMEBREW_GITHUB_API_TOKEN }}
         run: |
           # Release to Homebrew directly, bypassing the diff check as we already perform this check in the "prepare" job.
           make -- --dist-homebrew
 
       - name: Install via Homebrew
+        if: steps.github-release.outputs.release-url != ''
         run: |
           make install-brew

client/go/Makefile

@@ -52,10 +52,16 @@ dist-homebrew:
 #
 # $ make dist-github
 --dist-github: dist
-	gh release create v$(VERSION) --repo vespa-engine/vespa --notes-file $(CURDIR)/README.md --title "Vespa CLI $(VERSION)" \
-		$(DIST)/vespa-cli_$(VERSION)_sha256sums.txt \
-		$(DIST)/vespa-cli_$(VERSION)_*.zip \
-		$(DIST)/vespa-cli_$(VERSION)_*.tar.gz
+	RELEASE_URL="$(gh release create v$(VERSION)
+		--verify-tag
+		--repo vespa-engine/vespa
+		--notes-file $(CURDIR)/README.md
+		--title "Vespa CLI $(VERSION)"
+		$(DIST)/vespa-cli_$(VERSION)_sha256sums.txt
+		$(DIST)/vespa-cli_$(VERSION)_*.zip
+		$(DIST)/vespa-cli_$(VERSION)_*.tar.gz)"
+
+		echo $RELEASE_URL > /tmp/vespa-cli-release-url.txt
 
 dist-github:
 	go run cond_make.go --dist-github