* Bump gts from 5.3.1 to 6.0.2

Bumps [gts](https://github.com/google/gts) from 5.3.1 to 6.0.2.
- [Release notes](https://github.com/google/gts/releases)
- [Changelog](https://github.com/google/gts/blob/main/CHANGELOG.md)
- [Commits](google/gts@v5.3.1...v6.0.2)

---
updated-dependencies:
- dependency-name: gts
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

* run "npm run fix" with gts v6

Fixes needed because `gts` turned on `composite: true`:

* Add package.json to tsconfig. The file is referenced by TS files.

* Add a declarationDir `_types`. This directory is ignored. This is necessary because we can't omit `declarations`.

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Carlos (Goodwine) <2022649+Goodwine@users.noreply.github.com>

Bumps [immutable](https://github.com/immutable-js/immutable-js) from 4.3.7 to 5.0.2.
- [Release notes](https://github.com/immutable-js/immutable-js/releases)
- [Changelog](https://github.com/immutable-js/immutable-js/blob/main/CHANGELOG.md)
- [Commits](immutable-js/immutable-js@v4.3.7...v5.0.2)

---
updated-dependencies:
- dependency-name: immutable
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>