build(deps): bump mockito from 5.3.1 to 5.4.0

Bumps `mockito` from 5.3.1 to 5.4.0.

Updates `org.mockito:mockito-core` from 5.3.1 to 5.4.0
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v5.3.1...v5.4.0)

Updates `org.mockito:mockito-junit-jupiter` from 5.3.1 to 5.4.0
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v5.3.1...v5.4.0)

---
updated-dependencies:
- dependency-name: org.mockito:mockito-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.mockito:mockito-junit-jupiter
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 grpc = "1.56.0"
 log4j = "2.20.0"
-mockito = "5.3.1"
+mockito = "5.4.0"
 slf4j = "2.0.7"
 guava = "32.0.1-jre"
 assertj = "3.24.2"