Push gem GH action

.github/workflows/push_gem.yml

@@ -0,0 +1,39 @@
+---
+  'on':
+    push:
+      tags:
+      - v*
+  name: Push Gem
+  jobs:
+    push:
+      runs-on: ubuntu-latest
+      permissions:
+        contents: write
+        id-token: write
+      steps:
+      - uses: rubygems/configure-rubygems-credentials@main
+        with:
+          role-to-assume: ${{ secrets.RUBYGEMS_PUSH_ROLE }}
+      - uses: actions/checkout@v4
+      - name: Set remote URL
+        run: |
+          # Attribute commits to the last committer on HEAD
+          git config --global user.email "$(git log -1 --pretty=format:'%ae')"
+          git config --global user.name "$(git log -1 --pretty=format:'%an')"
+          git remote set-url origin "https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY"
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+          ruby-version: ruby
+      - name: Release
+        run: bundle exec rake release
+      - name: Wait for release to propagate
+        run: |
+          gem install rubygems-await
+          gem_tuple="$(ruby -rbundler/setup -rbundler -e '
+              spec = Bundler.definition.specs.find {|s| s.name == ARGV[0] }
+              raise "No spec for #{ARGV[0]}" unless spec
+              print [spec.name, spec.version, spec.platform].join(":")
+            ' "jwt")"
+          gem await "${gem_tuple}"

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 **Features:**
 
+- Build and push gem using a GH action [#612](https://github.com/jwt/ruby-jwt/pull/612) ([@anakinj](https://github.com/anakinj))
 - Your contribution here
 
 **Fixes and enhancements:**