Discussion: Enable Style/HashSyntax EnforcedShorthandSyntax again

Proposal

Remove:

Style/HashSyntax:
  EnforcedShorthandSyntax: never

This will enable the shorthand hash syntax (since the Rubocop default is always):

# bad
{foo: foo, bar: bar}

# good
{foo:, bar:}

I created an MR originally, but was asked to create an issue first so we can discuss and vote on it: !161622 (merged)

https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Style/HashSyntax

Background

In !140430 (merged) we disabled the new short hand Hash syntax, since we needed to support Ruby 3.0.

In the latest version of GitLab the minimum is 3.1.x.

I propose we enable this new syntax as is the Rubocop default, since it's more concise and doesn't appear to have any downsides.