Add tests for `sortObjectKeys` utility

Add a file `workspaces/util/src/__tests__/sortObjectKeys-test.ts`, for testing the `sortObjectKeys` utility.

To see some PRs that add tests, take a look at #288 and #290 for inspiration.

Create workspaces/util/src/__tests__/sortObjectKeys-test.ts and start by reading the sortObjectKeys utility. Review PRs #288 and #290 for the project's test style and patterns. Done means the new test file exercises the utility and passes with the existing test suite.

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