fix(java): Update to use JsonMapper

[booniepepper]

Description

Currently when building the Java SDK there is a warning that pops up due to using the deprecated ObjectMapper.configure(..., ...) methods.

> Task :compileJava
Note: /module/src/main/java/dev/openfga/api/invoker/JSON.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

References

https://github.com/FasterXML/jackson-databind/blob/2.16/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java#L2507-L2517

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected