ci: change permission on pypi

Author: tlambert03

.github/workflows/pypi.yml

@@ -48,8 +48,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
     permissions:
-      contents: read
-      packages: write
+      id-token: write
     steps:
       - name: Get sdist
         uses: actions/download-artifact@v4