Merge pull request swiftlang#80667 from eeckstein/fix-test

tests: restrict SILOptimizer/isolated_conformances.swift to macos and linux

Author: eeckstein

test/SILOptimizer/isolated_conformances.swift

@@ -9,6 +9,7 @@
 // REQUIRES: executable_test
 // REQUIRES: concurrency_runtime
 // REQUIRES: swift_feature_IsolatedConformances
+// REQUIRES: OS=macosx || OS=linux-gnu
 
 // UNSUPPORTED: back_deployment_runtime
 // UNSUPPORTED: back_deploy_concurrency