Allow manual runs of the release drafter

.github/workflows/release-drafter.yml

@@ -8,6 +8,12 @@ on:
   push:
     branches:
       - 'main'
+  workflow_dispatch:
+    inputs:
+      ref:
+        description: 'Git ref or SHA'
+        required: true
+        type: string
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -16,9 +22,13 @@ concurrency:
 jobs:
   release:
     runs-on: ubuntu-latest
+    env:
+      ref: ${{ inputs.ref || github.ref || github.sha }}
     steps:
       # Setup and install
       - uses: actions/checkout@v3
+        with:
+          ref: ${{ env.ref }}
       - uses: actions/setup-node@v3
         with:
           node-version-file: '.nvmrc'
@@ -51,7 +61,7 @@ jobs:
           name: v${{ steps.check.outputs.version }}
           tag: v${{ steps.check.outputs.version }}
           version: ${{ steps.check.outputs.version }}
-          commitish: ${{ github.sha }}
+          commitish: ${{ env.ref }}
           # NOTE(cemmer): `template` can't be supplied here, only `header` and `footer`, so have to pick one of those
           #   and make sure the .github/release-drafter.yml's `template` is empty-ish.
           header: ${{ steps.auto-changelog.outputs.MARKDOWN }}