PR created by the Librarian CLI to initialize a release. Merging this PR will auto trigger a release.

Librarian Version: v1.0.0
Language Image: us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:8e2c32496077054105bd06c54a59d6a6694287bc053588e24debe6da6920ad91
<details><summary>google-cloud-spanner: 3.60.0</summary>

## [3.60.0](https://togithub.com/googleapis/python-spanner/compare/v3.59.0...v3.60.0) (2025-12-10)

### Features

* make built-in metrics enabled by default (#1459) ([64aebe7e](https://togithub.com/googleapis/python-spanner/commit/64aebe7e))

* Exposing AutoscalingConfig in InstancePartition ([8b6f1540](https://togithub.com/googleapis/python-spanner/commit/8b6f1540))

* add support for experimental host (#1452) ([9535e5e0](https://togithub.com/googleapis/python-spanner/commit/9535e5e0))

* enable OpenTelemetry metrics and tracing by default (#1410) ([bb5095df](https://togithub.com/googleapis/python-spanner/commit/bb5095df))

* add cloud.region, request_tag and transaction_tag in span attributes (#1449) ([d37fb80a](https://togithub.com/googleapis/python-spanner/commit/d37fb80a))

* Add QueryAdvisorResult for query plan (PiperOrigin-RevId: 832425466) ([e08260fe](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Add Send and Ack mutations for Queues (PiperOrigin-RevId: 832425466) ([e08260fe](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Add Spanner location API (#1457) (PiperOrigin-RevId: 833474957) ([e08260fe](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

### Bug Fixes

* Deprecate credentials_file argument ([8b6f1540](https://togithub.com/googleapis/python-spanner/commit/8b6f1540))

* configure keepAlive time for gRPC TCP connections (#1448) ([efb2833e](https://togithub.com/googleapis/python-spanner/commit/efb2833e))

* Provide Spanner Option to disable metrics (#1460) ([f1ebc43b](https://togithub.com/googleapis/python-spanner/commit/f1ebc43b))

### Documentation

* Update description for the BatchCreateSessionsRequest and Session (PiperOrigin-RevId: 832425466) ([e08260fe](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Update description for the IsolationLevel (PiperOrigin-RevId: 832425466) ([e08260fe](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

</details>