Bump os-locale (add support for ESM dependencies)

[fregante]

• Picks up https://github.com/mozilla/addons-linter/pull/4989
• Partially includes https://github.com/mozilla/addons-linter/pull/5414
  • because Jest requires it to actually read transformIgnorePatterns correctly

os-locale v6 has huge savings

v6

v7

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.77%. Comparing base (cc07336) to head (83729b7).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #5415 +/- ## ======================================= Coverage 98.77% 98.77% ======================================= Files 51 51 Lines 2855 2855 Branches 867 867 ======================================= Hits 2820 2820 Misses 35 35 ```

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