ci: Fix duplicate GitHub release

sigstore/gh-action-sigstore-python 3.0 changed the default to now
release to GitHub including the sigstore artifacts.

So we tell the action not to perform the release.

Signed-off-by: BJ Hargrave <[email protected]>

Author: bjhargrave

.github/workflows/pypi.yml

@@ -113,6 +113,7 @@ jobs:
                   inputs: |
                       ./dist/*.tar.gz
                       ./dist/*.whl
+                  release-signing-artifacts: false
 
             - name: "Upload artifacts and signatures to GitHub release"
               run: |