chore: Bump @types/diff in the major-updates group across 1 directory

Bumps the major-updates group with 1 update in the / directory: [@types/diff](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/diff).


Updates `@types/diff` from 5.2.3 to 6.0.0
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/diff)

---
updated-dependencies:
- dependency-name: "@types/diff"
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: major-updates
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]