GHA: clean up whitespace (NFC)

Author: compnerd

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
             tag: DEVELOPMENT-SNAPSHOT-2022-10-09-a
             options: ''
 
-    steps:    
+    steps:
     - uses: compnerd/gha-setup-swift@main
       with:
         tag: ${{ matrix.tag }}