Stop running CI against JRuby and some CI config cleanup

.github/workflows/lint.yml

@@ -0,0 +1,27 @@
+name: Lint
+
+on: [push, pull_request]
+
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  lint:
+    strategy:
+      fail-fast: false
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4 # v3.3.0
+    # libyaml-dev is needed for psych, see https://github.com/ruby/setup-ruby/issues/409
+    - if: ${{ matrix.os == 'ubuntu-latest' }}
+      run: sudo apt install libyaml-dev
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@master
+      with:
+        ruby-version: 3.3
+        bundler-cache: true
+    - name: Run rubocop
+      run: bundle exec rubocop
+    - name: Sanity check for the format_generated_files task
+      run: bundle exec rake generate format_generated_files
+

.github/workflows/test.yml

@@ -11,6 +11,7 @@ jobs:
     with:
       # 2.7 breaks `test_parse_statements_nodoc_identifier_alias_method`
       min_version: 3.0
+      engine: cruby-truffleruby
 
   test:
     needs: ruby-versions
@@ -24,10 +25,6 @@ jobs:
             ruby: truffleruby
           - os: windows-latest
             ruby: truffleruby-head
-          - os: windows-latest
-            ruby: jruby
-          - os: windows-latest
-            ruby: jruby-head
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4 # v3.3.0
@@ -39,9 +36,6 @@ jobs:
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true # 'bundle install' and cache
-    # Avoid issues on these platforms
-    - if: ${{ matrix.ruby == '2.6' }}
-      run: gem update --system
     - name: Run test
       run: bundle exec rake
       env:
@@ -55,17 +49,3 @@ jobs:
       run: bundle exec rake rdoc
     - if: ${{ matrix.ruby == 'head' && startsWith(matrix.os, 'ubuntu') }}
       run: bundle exec rake install
-  lint:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: "3.3"
-          bundler-cache: true
-      - name: Run rubocop
-        run: bundle exec rubocop
-        # Just to make sure the format_generated_files task is working
-      - name: Sanity check for the format_generated_files task
-        run: bundle exec rake generate format_generated_files

Gemfile

@@ -12,6 +12,3 @@ group :development do
   gem 'gettext'
   gem 'prism', '>= 0.30.0'
 end
-
-# Workaround for https://github.com/mkristian/jar-dependencies/issues/86
-gem "jar-dependencies", "~> 0.4.0", platform: :jruby