chore: Update Flutter version

Author: fkorotkov

.cirrus.yml

@@ -6,11 +6,11 @@ docker_builder:
     # from https://flutter.dev/docs/development/tools/sdk/releases
     matrix:
       - DOCKER_TAG: latest
-        FLUTTER_VERSION: 3.38.3
+        FLUTTER_VERSION: 3.38.4
       - DOCKER_TAG: stable
-        FLUTTER_VERSION: 3.38.3
+        FLUTTER_VERSION: 3.38.4
       - DOCKER_TAG: beta
-        FLUTTER_VERSION: 3.39.0-0.1.pre
+        FLUTTER_VERSION: 3.39.0-0.2.pre
   version_script: docker --version
   setup_script:
     - docker buildx create --name multibuilder