chore: enable generation for django-google-spanner (#16880)

This PR re-enables generation for `django-google-spanner` which was
temporarily skipped due to
#16839

This PR was created using

```
export V=v0.11.0
go run github.com/googleapis/librarian/tool/cmd/builddockerimages@${V} --version ${V} --language python
docker run -u $(id -u):$(id -g) -v .:/repo -v ~/.cache:/.cache -w /repo docker.io/library/librarian-python:${V} generate -v django-google-spanner
```

Author: parthea

librarian.yaml

@@ -68,7 +68,6 @@ libraries:
       library_type: INTEGRATION
   - name: django-google-spanner
     version: 4.0.3
-    skip_generate: true
     python:
       library_type: INTEGRATION
   - name: gapic-generator

packages/django-google-spanner/.repo-metadata.json

@@ -4,7 +4,6 @@
     "language": "python",
     "library_type": "INTEGRATION",
     "name": "django-google-spanner",
-    "name_pretty": "Cloud Spanner Django",
     "release_level": "stable",
     "repo": "googleapis/google-cloud-python"
 }