chore(deps): bump google/cloud-sdk in /.dev/spanner (#734)

Bumps google/cloud-sdk from 494.0.0-emulators to 495.0.0-emulators.

---
updated-dependencies:
- dependency-name: google/cloud-sdk
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.dev/spanner/Dockerfile

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM google/cloud-sdk:494.0.0-emulators
+FROM google/cloud-sdk:495.0.0-emulators
 
 ENV SPANNER_PROJECT_ID=local
 ENV SPANNER_INSTANCE_ID=local