Update github actions. Add ruby 3.2.0 to test matrix, use latest OS versions.

Author: cfis

.github/workflows/mri.yml

@@ -1,6 +1,10 @@
 name: CI
 
-on: [push, pull_request, workflow_dispatch]
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
 
 jobs:
   build:
@@ -16,26 +20,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-20.04, ubuntu-18.04, macos-11, windows-2022 ]
-        ruby: [ 3.1, '3.0', 2.7 ]
-
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        ruby: ['2.7', '3.0', '3.1', '3.2']
     steps:
-      - name: repo checkout
-        uses: actions/checkout@v2
-
-      - name: load ruby
-        uses: MSP-Greg/setup-ruby-pkgs@v1
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           apt-get: libxml2-dev
           # brew: libxml2
           mingw: libxml2
-          bundler-cache: true
-        timeout-minutes: 10
-
-      - name: compile
-        run:  bundle exec rake compile
-
-      - name: test
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
         timeout-minutes: 10
+      - name: Build
+        run: bundle exec rake compile
+      - name: Test
         run: bundle exec rake test