chore: Update generation configuration at Sat Sep 27 02:26:40 UTC 2025 (#4095)

* chore: Update generation configuration at Sat Sep 27 02:26:40 UTC 2025

* chore: generate libraries at Sat Sep 27 02:27:10 UTC 2025

Author: cloud-java-bot

java-spanner/generation_config.yaml

@@ -1,5 +1,5 @@
 gapic_generator_version: 2.62.2
-googleapis_commitish: 329ace5e3712a2e37d6159d4dcd998d8c73f261e
+googleapis_commitish: 31b413bc4feb03f6849c718048c2b9998561b5fa
 libraries_bom_version: 26.68.0
 libraries:
   - api_shortname: spanner