Revert "switch to voxpupuli-rubocop; generate ruby CI matrix dynamically"

This reverts commit 92538f0.

Author: bastelfreak

.github/workflows/lint.yaml

@@ -0,0 +1,27 @@
+name: Linting
+
+on:
+  pull_request:
+    types: [opened, reopened, edited, synchronize]
+    paths:
+      - .github/workflows/lint.yaml
+      - '**.rb'
+
+jobs:
+
+  rubocop:
+    name: Rubocop
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.7
+      - name: Install rubocop
+        run: |
+          gem install rubocop --version 1.9.1
+          gem install rubocop-rake
+      - name: Run rubocop
+        run: rubocop --display-cop-names --display-style-guide --parallel

.github/workflows/tests.yaml

@@ -11,30 +11,14 @@ permissions:
   contents: read
 
 jobs:
-  rubocop_and_matrix:
-    runs-on: ubuntu-24.04
-    outputs:
-      ruby: ${{ steps.ruby.outputs.versions }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Ruby ${{ matrix.ruby }}
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: "3.4"
-          bundler-cache: true
-      - name: Run Rubocop
-        run: bundle exec rake rubocop
-      - id: ruby
-        uses: voxpupuli/ruby-version@v1
 
   unit:
-    needs: rubocop_and_matrix
     name: "Ruby ${{ matrix.ruby }} ${{ matrix.os }}"
     strategy:
       fail-fast: false
       matrix:
         os: [ubuntu-24.04, windows-latest]
-        ruby: ${{ steps.ruby.outputs.versions }}
+        ruby: ['3.2', '3.3']
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout repository
@@ -60,7 +44,6 @@ jobs:
 
   tests:
     needs:
-      - rubocop_and_matrix
       - unit
     runs-on: ubuntu-24.04
     name: Test suite