Add a windows job to CI

.github/workflows/ci.yml

@@ -6,20 +6,24 @@ concurrency:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}-latest
     timeout-minutes: 10
 
     strategy:
       fail-fast: false
       matrix:
         ruby: [2.3, 2.4, 2.5, 2.6, 2.7, '3.0', 3.1, 3.2, 3.3, jruby, truffleruby]
+        os: [ubuntu]
+        include:
+          - ruby: 3.3
+            os: windows
 
     env:
       JAVA_OPTS: '-Xmx1024m'
       RUBYOPT: '-w'
       JRUBY_OPTS: '--dev'
 
-    name: "Tests: Ruby ${{ matrix.ruby }}"
+    name: "Tests: Ruby ${{ matrix.ruby }} - ${{ matrix.os }}"
     steps:
     - name: Clone Repo
       uses: actions/checkout@v4

spec/concurrent/channel/integration_spec.rb

@@ -68,7 +68,7 @@
     end
 
     specify 'default-selection.rb' do
-      skip('flaky') if Concurrent.on_jruby? || Concurrent.on_truffleruby?
+      skip('flaky') if Concurrent.on_jruby? || Concurrent.on_truffleruby? || Concurrent.on_windows?
 expected = <<-STDOUT
     .
     .

spec/concurrent/promises_spec.rb

@@ -758,6 +758,7 @@ def behaves_as_delay(delay, value)
   describe 'value!' do
     %w[with without].each do |timeout|
       it "does not return spuriously #{timeout} timeout" do
+        skip "SIGHUP not supported" if Concurrent.on_windows?
         # https://github.com/ruby-concurrency/concurrent-ruby/issues/1015
         trapped = false
         original_handler = Signal.trap(:SIGHUP) { trapped = true }