dependabot: bump com.uber.nullaway:nullaway from 0.12.15 to 0.13.1

Bumps [com.uber.nullaway:nullaway](https://github.com/uber/NullAway) from 0.12.15 to 0.13.1.
- [Release notes](https://github.com/uber/NullAway/releases)
- [Changelog](https://github.com/uber/NullAway/blob/master/CHANGELOG.md)
- [Commits](uber/NullAway@v0.12.15...v0.13.1)

---
updated-dependencies:
- dependency-name: com.uber.nullaway:nullaway
  dependency-version: 0.13.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 spotless = "8.2.0"
 errorprone-plugin = "5.0.0"
 errorprone-core = "2.46.0"
-nullaway = "0.12.15"
+nullaway = "0.13.1"
 palantir = "2.83.0"
 
 [libraries]