iterate on workflow syntax

Author: arik-so

.github/workflows/swift.yml

@@ -124,7 +124,7 @@ jobs:
     test_bindings_with_sanitizer:
         runs-on: ubuntu-20.04
         steps:
-            -   uses: ./.github/workflows/swift-prep
+            -   uses: ./.github/workflows/swift-prep.yml
             -   name: Test Swift bindings package without address sanitizer
                 run: |
                     python ci/toggle_address_sanitation_library.py off