CI: Introduce ruby_versions.yml to add supported Ruby versions automatically (#124)

Signed-off-by: Shizuo Fujita <fujita@clear-code.com>

Author: Watson1978

.github/workflows/unit-test.yml

@@ -4,21 +4,24 @@ on:
     branches: [master]
   pull_request:
     branches: [master]
+  schedule:
+    - cron: '0 0 1 * *'
 jobs:
+  ruby-versions:
+    uses: ruby/actions/.github/workflows/ruby_versions.yml@master
+    with:
+      engine: cruby
+      min_version: 2.7
   test:
+    needs: ruby-versions
     runs-on: ${{ matrix.os }}
-    continue-on-error: ${{ matrix.experimental }}
+    continue-on-error: ${{ matrix.ruby == 'head' }}
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '3.4', '3.3', '3.2', '3.1', '3.0', '2.7' ]
+        ruby: ${{ fromJson(needs.ruby-versions.outputs.versions) }}
         os:
           - windows-latest
-        experimental: [false]
-        include:
-          - ruby: 'head'
-            os: windows-latest
-            experimental: true
     name: Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v6
@@ -29,7 +32,6 @@ jobs:
       run: |
         ruby --version
         gem --version
-        gem install bundler rake
         ridk exec bundle install --jobs 4 --retry 3
     - name: Unit Test
       run: |