ci: delete the old generic package file right before re-uploading it

The second publish failed with HTTP 409 (package file already exists) because Gitea does not overwrite
a generic package file. The previous copy of each file is now deleted just before its upload.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.github/workflows/publish-tdlm.yml

@@ -138,6 +138,17 @@ jobs:
 
           def put(name: str, data: bytes):
               url = upload_root + "/" + urllib.parse.quote(name, safe="")
+              # Gitea refuses to overwrite a generic package file (HTTP 409), so the previous copy of this one
+              # file is deleted right before it is uploaded again (keeps the gap without a file as short as possible).
+              delete = urllib.request.Request(url, method="DELETE")
+              delete.add_header("Authorization", "token " + token)
+              delete.add_header("User-Agent", "tdlm-hmcl-publish")
+              try:
+                  with urllib.request.urlopen(delete, timeout=300) as response:
+                      response.read()
+              except urllib.error.HTTPError as exc:
+                  if exc.code != 404:
+                      raise SystemExit("HTTP %s deleting the old %s: %s" % (exc.code, name, exc.read()[:300]))
               request = urllib.request.Request(url, data=data, method="PUT")
               request.add_header("Authorization", "token " + token)
               request.add_header("Content-Type", "application/octet-stream")