ci(ios): strip CRLF from ffmpeg plugin scripts before pod install

The ffmpeg_kit_flutter_new_full pub package ships setup_ios.sh with CRLF line endings, so its podspec prepare_command failed with '/bin/bash^M: bad interpreter'. Normalize the plugin's shell scripts in the pub cache before building iOS.

.github/workflows/release.yml

@@ -257,6 +257,15 @@ jobs:
       - name: Get Flutter dependencies
         run: flutter pub get
 
+      - name: Normalize ffmpeg plugin shell scripts (strip CRLF)
+        run: |
+          find "$HOME/.pub-cache/hosted" -path "*ffmpeg_kit_flutter_new_full*/scripts/*.sh" -type f -print0 |
+            while IFS= read -r -d '' f; do
+              perl -pi -e 's/\r$//' "$f"
+              chmod +x "$f"
+              echo "Normalized line endings: $f"
+            done
+
       - name: Generate app icons
         run: dart run flutter_launcher_icons