Check release existence, not just tag, before skipping

The tag may exist from a prior run that lacked the release
creation step.  Now the job creates the tag if missing, then
independently checks if the release exists before deciding
to skip.

Author: renaudallard

.github/workflows/build.yml

@@ -93,13 +93,15 @@ jobs:
             echo "Could not extract version"
             exit 1
           fi
-          if git rev-parse "v${ver}" >/dev/null 2>&1; then
-            echo "Tag v${ver} already exists, skipping"
+          if ! git rev-parse "v${ver}" >/dev/null 2>&1; then
+            echo "Creating tag v${ver}"
+            git tag "v${ver}"
+            git push origin "v${ver}"
+          fi
+          if gh release view "v${ver}" --repo "${{ github.repository }}" >/dev/null 2>&1; then
+            echo "Release v${ver} already exists, skipping"
             exit 0
           fi
-          echo "Creating tag v${ver}"
-          git tag "v${ver}"
-          git push origin "v${ver}"
           echo "Creating release v${ver}"
           gh release create "v${ver}" \
             --repo "${{ github.repository }}" \