cicd: Added docker credential secrets to release workflow

Author: jruaux

.github/workflows/release.yml

@@ -37,4 +37,6 @@ jobs:
     with:
       tags: fieldengineering/redis-kafka-connect:latest,fieldengineering/redis-kafka-connect:${{ github.event.inputs.version }}
     secrets:
-      github-token: ${{ secrets.GIT_ACCESS_TOKEN }}
+      github-token: ${{ secrets.GIT_ACCESS_TOKEN }}
+      docker-username: ${{ secrets.DOCKER_USERNAME }}
+      docker-password: ${{ secrets.DOCKER_PASSWORD }}