Docker image shouldn't be published on PRs

This action would run for every PR action which means it'll create a docker image every time the CI runs on contributions.

.github/workflows/docker.yml

@@ -10,7 +10,6 @@
 name: Publish Docker image
 
 on:
-  pull_request:
   push:
     branches:
       - master
@@ -58,4 +57,4 @@ jobs:
           context: .
           push: ${{ github.event_name == 'push' }}
           tags: "ghcr.io/ggerganov/llama.cpp:${{ matrix.config.tag }}"
-          file: ${{ matrix.config.dockerfile }}
+          file: ${{ matrix.config.dockerfile }}