Add manual Docker publishing trigger in GH action workflow

.github/workflows/publish.yml

@@ -1,6 +1,13 @@
 name: Publish Docker image
 
 on:
+  workflow_dispatch:
+    inputs:
+      ref:
+        description: 'Git ref (tag or commit SHA) to build'
+        required: true
+        type: string 
+        default: 'main'
   push:
     tags:
       - 'v*'
@@ -33,6 +40,8 @@ jobs:
     steps:
       - name: Check out the repo
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.ref || github.ref }}
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3