ci: add workflow_dispatch trigger to publish workflow

Allows manually re-running the publish pipeline for an existing tag.

Author: cryptomilk

.github/workflows/publish.yml

@@ -4,6 +4,11 @@ on:
   push:
     tags:
       - "v*"
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Tag to publish (e.g. v1.0.0)"
+        required: true
 
 jobs:
   build:
@@ -12,6 +17,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0  # needed for setuptools_scm to derive version from tags
+          ref: ${{ github.event.inputs.tag || github.ref }}
 
       - uses: actions/setup-python@v5
         with: