ci: add release gem workflows

Author: initdc

.github/workflows/main.yml

@@ -9,7 +9,7 @@ on:
       - dev
 
 concurrency:
-  group: ${{ github.sha }}
+  group: ${{ github.workflow }}-${{ github.sha }}
   cancel-in-progress: true
 
 jobs:

.github/workflows/release.yml

@@ -0,0 +1,39 @@
+name: Release Gem
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - 'v*'
+  release:
+    types:
+      - created
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  push:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: write
+      id-token: write
+
+    # If you configured a GitHub environment on RubyGems, you must use it here.
+    environment: release
+
+    steps:
+      # Set up
+      - uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+          ruby-version: ruby
+
+      - name: Release Gem
+        uses: rubygems/release-gem@v1