Enable Trailing Comma Rule in Prettier - #51451

As part of Molly's upgrade to Prettier (2.8.7) #51065, we now have an override to disable the trailing comma rule

The default value for the trailing comma rule changed as part of the Prettier upgrade https://prettier.io/docs/en/options.html#trailing-commas to "es5":

"es5" - Trailing commas where valid in ES5 (objects, arrays, etc.). No trailing commas in type parameters in TypeScript.

This PR removes the override to use the default value and updates existing files with the automated --fix feature. When I first removed the override, I ran bundle exec rake lint:javascript and got

✖ 26315 problems (26315 errors, 0 warnings)
  26315 errors and 0 warnings potentially fixable with the `--fix` option.

I then ran yarn lint:js -- --fix which yielded

➜  code-dot-org git:(meg/lint-danging-comma) ✗ gc -m "Run yarn lint:js -- --fix"
[meg/lint-danging-comma 764ee0ecc19] Run yarn lint:js -- --fix
 2633 files changed, 26367 insertions(+), 26315 deletions(-)

I committed those files, all of which were in the apps directory, and then ran bundle exec rake lint:javascript again and got no errors.

Links

Argument to enable trailing commas: https://medium.com/@nikgraf/why-you-should-enforce-dangling-commas-for-multiline-statements-d034c98e36f8

Testing story

Deployment strategy

Follow-up work

Privacy

Security

Caching

PR Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked