feat: build branch name on pr

Author: reednaa

.github/workflows/docker-build.yml

@@ -33,6 +33,7 @@ jobs:
             type=raw,value=latest,enable={{is_default_branch}}
             type=ref,event=branch
             type=ref,event=pr
+            type=ref,event=pr,value={{branch}}
             type=semver,pattern=v{{version}}
             type=semver,pattern=v{{major}}
             type=semver,pattern=v{{major}}.{{minor}}