Update docker.yaml to include branch filter

Add branch filter to workflow trigger for Docker build.

Author: TylerS1066

.github/workflows/docker.yaml

@@ -4,6 +4,8 @@ on:
   workflow_run:
     workflows: ["Gradle CI"]
     types: [completed]
+    branches:
+      - '*'
 
 jobs:
   build-and-push: