ci: migrate Swift Format workflow to Linux runners

Author: coenttb

.github/workflows/swift-format.yml

@@ -12,15 +12,12 @@ concurrency:
 jobs:
   swift_format:
     name: swift-format
-    runs-on: macos-26
+    runs-on: ubuntu-latest
     permissions:
       contents: write
     steps:
       - uses: actions/checkout@v5
 
-      - name: Select Xcode
-        run: sudo xcode-select -s /Applications/Xcode_26.0.app
-
       - name: Cache swift-format
         id: cache-swift-format
         uses: actions/cache@v4