ci: create release instead

.github/workflows/slsa-publish.yml

@@ -1,12 +1,14 @@
-name: publish (slsa 3)
+name: release (slsa 3)
 on:
-  workflow_dispatch:
-  release:
-    types: [created]
+  push:
+    tags:
+    - '*'
 
 jobs:
   build:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
     outputs:
       hashes: ${{ steps.hash.outputs.hashes }}
 
@@ -31,8 +33,9 @@ jobs:
           HASHES=$(sha256sum * | base64 -w0)
           echo "hashes=$HASHES" >> "$GITHUB_OUTPUT"
 
-      - name: upload artifacts
+      - name: release
         uses: softprops/[email protected]
+        if: startsWith(github.ref, 'refs/tags/')
         with:
           files: |
             dist/*.whl