Enable iOS GitHub Actions workflow.

Enable iOS GitHub Actions workflow added in swiftlang/github-workflows#169.

Author: grynspan

.github/workflows/pull_request.yml

@@ -21,6 +21,8 @@ jobs:
       windows_swift_versions: '["nightly-main", "nightly-6.2"]'
       enable_macos_checks: true
       macos_exclude_xcode_versions: '[{"xcode_version": "16.2"}, {"xcode_version": "16.3"}, {"xcode_version": "16.4"}]'
+      enable_ios_checks: true
+      ios_host_exclude_xcode_versions: '[{"xcode_version": "16.2"}, {"xcode_version": "16.3"}, {"xcode_version": "16.4"}]'
       enable_wasm_sdk_build: true
   soundness:
     name: Soundness