updating docker release action

Author: JoeBeeContrast

.github/workflows/docker-release.yml

@@ -1,10 +1,8 @@
 name: Build and Push Docker Image on Release
 
 on:
-  push:
-    branches: [ "main" ]
-  pull_request:
-    branches: [ "main" ]
+  release:
+    types: [published]
 
 env:
   DOCKER_CONTENT_TRUST_REPOSITORY_PASSPHRASE: "${{secrets.DIGICERT_PKEY_PASSPHRASE}}"