add release workflow

.github/workflows/actions.lock

@@ -6,6 +6,10 @@ workflows:
     '.github/workflows/check.yml':
         - 'actions/checkout@v7.0.1'
         - 'ruby/setup-ruby@v1.335.0'
+    '.github/workflows/release.yml':
+        - 'actions/checkout@v7.0.1'
+        - 'ruby/setup-ruby@v1.335.0'
+        - 'rubygems/release-gem@v1.4.1'
     '.github/workflows/test.yml':
         - 'actions/checkout@v7.0.1'
         - 'actions/setup-node@v7.1.0'
@@ -26,3 +30,15 @@ dependencies:
         commit: 'sha1-7f797815d8adceb1c412e7abefdd1ab4abc47a5f'
         owner_id: 210414
         repo_id: 231208785
+    'rubygems/configure-rubygems-credentials@dc5a8d8553e6ee01fc26761a49e99e733d17954a':
+        ref: 'v2.1.0'
+        commit: 'sha1-dc5a8d8553e6ee01fc26761a49e99e733d17954a'
+        owner_id: 208761
+        repo_id: 631633510
+    'rubygems/release-gem@v1.4.1':
+        ref: 'v1.4.1'
+        commit: 'sha1-7f9650160c1a4e7989fdc9855807bdbd421d8b6b'
+        owner_id: 208761
+        repo_id: 731435765
+        uses:
+            - 'rubygems/configure-rubygems-credentials@dc5a8d8553e6ee01fc26761a49e99e733d17954a'

.github/workflows/release.yml

@@ -0,0 +1,26 @@
+name: Release
+
+on:
+  workflow_dispatch:
+
+jobs:
+  release:
+    if: github.ref_name == github.event.repository.default_branch
+
+    runs-on: ubuntu-latest
+
+    environment: release
+
+    permissions:
+      contents: write
+      id-token: write
+
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1.335.0
+        with:
+          ruby-version: '4.0'
+          bundler-cache: true
+      - name: Release gem
+        uses: rubygems/release-gem@v1.4.1