fix: remove UI theme

[d-jeffery]

Description

openfgaintellijplugin-0.1.2.zip

Theme in VSCode Dark Modern:

References

• fixes https://github.com/openfga/intellij-plugin/issues/27

Review Checklist

• [x] 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]
• [x] 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