Skip existing when retrying upload-pypi.py (#19305)

The upload script has been pretty flaky for me. Now rerunning skips the
wheels that have already been uploaded, so the upload should always
eventually finish after enough retries.

Work on #19174.

Author: JukkaL

misc/upload-pypi.py

@@ -108,7 +108,7 @@ def tmp_twine() -> Iterator[Path]:
 def upload_dist(dist: Path, dry_run: bool = True) -> None:
     with tmp_twine() as twine:
         files = [item for item in dist.iterdir() if item_ok_for_pypi(item.name)]
-        cmd: list[Any] = [twine, "upload"]
+        cmd: list[Any] = [twine, "upload", "--skip-existing"]
         cmd += files
         if dry_run:
             print("[dry run] " + " ".join(map(str, cmd)))