disable cxx interop 5.8/5.9

Author: rnro

.github/workflows/pull_request.yml

@@ -23,6 +23,9 @@ jobs:
     cxx-interop:
         name: Cxx interop
         uses: apple/swift-nio/.github/workflows/cxx_interop.yml@main
+        with:
+            linux_5_9_enabled: false
+            linux_5_10_enabled: false
 
     swift-6-language-mode:
         name: Swift 6 Language Mode