Update RubyGems in GitHub Actions CI (#406)

* Update RubyGems in GitHub Actions CI
* Allow `WARN: Unresolved or ambiguous specs during Gem::Specification.reset:` for Ruby 3.0.x and TruffleRuby

  The latest RubyGems version supported on Ruby 3.0 is 3.5.23,
  and TruffleRuby does not support `gem update --system` (its bundled
  RubyGems version is 3.5.22). Both of these are lower than 3.6.0,
  so the warning is expected in these environments.

Author: yahonda

.github/workflows/ruby.yml

@@ -16,13 +16,24 @@ jobs:
           - '3.4'
           - jruby
           - truffleruby
+        include:
+          - ruby: '3.0'
+            rubygems_version: '3.5.23'
+          - ruby: '3.1'
+            rubygems_version: '3.6.9'
     name: Ruby ${{ matrix.ruby }}
     steps:
       - uses: actions/checkout@v2
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
+      - name: Update RubyGems
+        env:
+          RUBYGEMS_VERSION: ${{ matrix.rubygems_version }}
+        run: |
+            gem update --system ${RUBYGEMS_VERSION:-}
+            gem -v
       - name: Install dependencies
         run: bundle install --jobs 4 --retry 3
       - name: Run tests

spec/integration_spec.rb

@@ -11,7 +11,14 @@
   subject { sh(command) }
 
   it "must invoke the CLI class" do
-    expect(subject).to eq("bundler-audit #{Bundler::Audit::VERSION}#{$/}")
+    expected = "bundler-audit #{Bundler::Audit::VERSION}#{$/}"
+
+    if RUBY_VERSION.start_with?("3.0") || RUBY_ENGINE == "truffleruby"
+      # Allow `WARN: Unresolved or ambiguous specs during Gem::Specification.reset:` for Ruby 3.0.x and TruffleRuby
+      expect(subject).to include(expected)
+    else
+      expect(subject).to eq(expected)
+    end
   end
 end
 
@@ -26,6 +33,13 @@
   subject { sh(command) }
 
   it "must invoke the CLI class" do
-    expect(subject).to eq("bundler-audit #{Bundler::Audit::VERSION}#{$/}")
+    expected = "bundler-audit #{Bundler::Audit::VERSION}#{$/}"
+
+    if RUBY_VERSION.start_with?("3.0") || RUBY_ENGINE == "truffleruby"
+      # Allow `WARN: Unresolved or ambiguous specs during Gem::Specification.reset:` for Ruby 3.0.x and TruffleRuby
+      expect(subject).to include(expected)
+    else
+      expect(subject).to eq(expected)
+    end
   end
 end