fix: do not trigger build workflows after merging to main or for release PRs

Since all merges to the main branch must be a fast-forward rebase, CI
builds should not be run when merged to main. They are run via the
pull request before merging.

The continuous_integration workflow should be triggered for pull requests
targeting main.

The experimental_ruby_builds workflow should only be triggered manually via
the GitHub UI.

Move unneeded builds from continuous_integration to experimental_ruby_builds

There is not a good reason to have a specific builds in the
continuous_integration workflow on Windows, or using JRuby or TruffleRuby.

Author: jcouball

.github/workflows/main.yml renamed to .github/workflows/continuous_integration.yml

@@ -1,28 +1,31 @@
-name: CI Build
+name: Continuous Integration
 
 on:
-  push:
-    branches: [ main ]
-
   pull_request:
-     branches: [ main ]
+    branches: [main]
+
+  workflow_dispatch:
 
 jobs:
   build:
+    name: Ruby ${{ matrix.ruby }} on ${{ matrix.operating-system }}
+
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'pull_request' && !startsWith(github.event.pull_request.head.ref, 'release-please--'))
+
+    runs-on: ${{ matrix.operating-system }}
     continue-on-error: true
 
+    env:
+      FAIL_ON_LOW_COVERAGE: ${{ matrix.fail_on_low_coverage }}
+
     strategy:
+      fail-fast: false
       matrix:
-        ruby: ['3.1', '3.4', jruby-head]
+        ruby: ["3.1", "3.4"]
         operating-system: [ubuntu-latest]
-        include:
-          - ruby: '3.1'
-            operating-system: windows-latest
-          - ruby: jruby-head
-            operating-system: windows-latest
-
-    name: Ruby ${{ matrix.ruby }} on ${{ matrix.operating-system }}
-    runs-on: ${{ matrix.operating-system }}
+        fail_on_low_coverage: [true]
 
     steps:
       - name: Checkout

.github/workflows/release.yml

@@ -1,51 +1,51 @@
 ---
-name: Release Gem
-description: |
-  This workflow creates a new release on GitHub and publishes the gem to
-  RubyGems.org.
-
-  The workflow uses the `googleapis/release-please-action` to handle the
-  release creation process and the `rubygems/release-gem` action to publish
-  the gem.
-
-on:
-  push:
-    branches: ["main"]
-
-  workflow_dispatch:
-
-jobs:
-  release:
-    runs-on: ubuntu-latest
-
-    environment:
-      name: RubyGems
-      url: https://rubygems.org/gems/github_pages_rake_tasks
-
-    permissions:
-      contents: write
-      pull-requests: write
-      id-token: write
-
-    steps:
-      - name: Checkout project
-        uses: actions/checkout@v4
-
-      - name: Create release
-        uses: googleapis/release-please-action@v4
-        id: release
-        with:
-          token: ${{ secrets.AUTO_RELEASE_TOKEN }}
-          config-file: release-please-config.json
-          manifest-file: .release-please-manifest.json
-
-      - name: Setup ruby
-        uses: ruby/setup-ruby@v1
-        if: ${{ steps.release.outputs.release_created }}
-        with:
-          bundler-cache: true
-          ruby-version: ruby
-
-      - name: Push to RubyGems.org
-        uses: rubygems/release-gem@v1
-        if: ${{ steps.release.outputs.release_created }}
+  name: Release Gem
+  description: |
+    This workflow creates a new release on GitHub and publishes the gem to
+    RubyGems.org.
+
+    The workflow uses the `googleapis/release-please-action` to handle the
+    release creation process and the `rubygems/release-gem` action to publish
+    the gem.
+
+  on:
+    push:
+      branches: ["main"]
+
+    workflow_dispatch:
+
+  jobs:
+    release:
+      runs-on: ubuntu-latest
+
+      environment:
+        name: RubyGems
+        url: https://rubygems.org/gems/process_executer
+
+      permissions:
+        contents: write
+        pull-requests: write
+        id-token: write
+
+      steps:
+        - name: Checkout project
+          uses: actions/checkout@v4
+
+        - name: Create release
+          uses: googleapis/release-please-action@v4
+          id: release
+          with:
+            token: ${{ secrets.AUTO_RELEASE_TOKEN }}
+            config-file: release-please-config.json
+            manifest-file: .release-please-manifest.json
+
+        - name: Setup ruby
+          uses: ruby/setup-ruby@v1
+          if: ${{ steps.release.outputs.release_created }}
+          with:
+            bundler-cache: true
+            ruby-version: ruby
+
+        - name: Push to RubyGems.org
+          uses: rubygems/release-gem@v1
+          if: ${{ steps.release.outputs.release_created }}