Allow build on any branch, tag, or commit.

Author: chungyc

.github/workflows/release.yaml

@@ -3,7 +3,15 @@ concurrency: build
 permissions: read-all
 
 on:
+
   workflow_dispatch:
+    inputs:
+      reference:
+        description: Branch, tag, or hash of commit to build.
+        required: false
+        default: main
+        type: string
+
   push:
     tags: ['v*']  # Build and publish image on release.
 
@@ -21,6 +29,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3
+        with:
+          ref: ${{ inputs.reference }}
 
       - name: Log in to the Container registry
         uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9