Update pull-transifex.yml (#170)

Revert swift-actions/setup-swift to `v2.4.0` after the automatic upgrade to `v3.0.0beta1` left the workflow with a broken action.

Author: felix-schwarz

.github/workflows/pull-transifex.yml

@@ -34,7 +34,7 @@ jobs:
           beautifyJSON "ownCloudUI/Resources/Localizable.xcstrings"         
 
       - name: Setup Swift
-        uses: swift-actions/setup-swift@364295d9c23900ce04d4e5cc708387921b4e50f9 # v3
+        uses: swift-actions/setup-swift@7ca6abe6b3b0e8b5421b88be48feee39cbf52c6a # v2.4.0
 
       - name: Build ocstringstool
         run: |