update google-cloud-spanner to include testing extras

See: googleapis/python-spanner#1193

Author: rbarrette

airflow/providers/google/provider.yaml

@@ -138,9 +138,7 @@ dependencies:
   - google-cloud-pubsub>=2.19.0
   - google-cloud-redis>=2.12.0
   - google-cloud-secret-manager>=2.16.0
-  # Google Cloud spanner 3.49.0 is excluded due to a bug in the library (missing grpc_interceptor)
-  # See https://github.com/googleapis/python-spanner/issues/1193
-  - google-cloud-spanner>=3.11.1,!=3.49.0
+  - google-cloud-spanner[testing]>=3.11.1
   - google-cloud-speech>=2.18.0
   - google-cloud-storage>=2.7.0
   - google-cloud-storage-transfer>=1.4.1

generated/provider_dependencies.json

@@ -643,7 +643,7 @@
       "google-cloud-redis>=2.12.0",
       "google-cloud-run>=0.10.0",
       "google-cloud-secret-manager>=2.16.0",
-      "google-cloud-spanner>=3.11.1,!=3.49.0",
+      "google-cloud-spanner[testing]>=3.11.1",
       "google-cloud-speech>=2.18.0",
       "google-cloud-storage-transfer>=1.4.1",
       "google-cloud-storage>=2.7.0",