Use commit hash for github workflows

Author: fboemer

.github/workflows/ci.yml

@@ -16,16 +16,17 @@ env:
   # Keep versions in sync with README
   SWIFTLINT_VERSION: 0.62.2
   SWIFTFORMAT_VERSION: 0.58.6
+  GITHUB_WORKFLOWS_VERSION: a5ed4ea197a097063371677688296b0c46c318d8 # 0.0.6
 jobs:
   soundness:
     name: soundness
-    uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
+    uses: swiftlang/github-workflows/.github/workflows/soundness.yml@${{ env.GITHUB_WORKFLOWS_VERSION }}
     with:
       docs_check_container_image: swift:6.2.2-noble
       format_check_enabled: false
   tests:
     name: swifttests
-    uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
+    uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@{{ env.GITHUB_WORKFLOWS_VERSION }}
     with:
       enable_windows_checks: false
       linux_exclude_swift_versions: "[{\"swift_version\": \"5.9\"}, {\"swift_version\": \"5.10\"}, {\"swift_version\": \"6.0\"}, {\"swift_version\": \"6.1\"}]"