Re-enable TruffleRuby in CI matrix

TruffleRuby was dropped when adding the `rbs` dependency because
`rbs` has a C extension. Re-enable it to verify whether TruffleRuby
can handle `rbs` 4.0+ (JRuby remains excluded).

Author: st0012

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
     with:
       min_version: 3.2
       versions: '["mswin"]'
-      engine: cruby
+      engine: cruby-truffleruby
 
   test:
     needs: ruby-versions
@@ -26,6 +26,10 @@ jobs:
         ruby: ${{ fromJson(needs.ruby-versions.outputs.versions) }}
         os: [ubuntu-latest, macos-latest, windows-latest]
         exclude:
+          - os: windows-latest
+            ruby: truffleruby
+          - os: windows-latest
+            ruby: truffleruby-head
           - os: macos-latest
             ruby: mswin
           - os: ubuntu-latest