build(deps): bump org.openapitools:jackson-databind-nullable

Bumps [org.openapitools:jackson-databind-nullable](https://github.com/OpenAPITools/jackson-databind-nullable) from 0.2.1 to 0.2.6.
- [Release notes](https://github.com/OpenAPITools/jackson-databind-nullable/releases)
- [Commits](OpenAPITools/jackson-databind-nullable@jackson-databind-nullable-0.2.1...v0.2.6)

---
updated-dependencies:
- dependency-name: org.openapitools:jackson-databind-nullable
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

gradle/libs.versions.toml

@@ -10,7 +10,7 @@ httpMockServer = "5.15.0"
 jetbrains-annotations = "24.0.1"
 jupiter = "5.9.2"
 okhttp = "4.10.0"
-openApiTools = "0.2.1"
+openApiTools = "0.2.6"
 picocli = "4.6.3"
 
 [libraries]