Fix shadowing outer local variable and other warnings

[Spone]

Summary

This fixes the following warnings that are output when running the tests:

/home/runner/work/view_component/view_component/lib/view_component/slotable_v2.rb:279: warning: shadowing outer local variable - args
/home/runner/work/view_component/view_component/app/helpers/preview_helper.rb:30: warning: shadowing outer local variable - template
/home/runner/work/view_component/view_component/test/sandbox/app/components/jbuilder_component.json.jbuilder:1: warning: `frozen_string_literal' is ignored after any tokens
/home/runner/work/view_component/view_component/test/view_component/slotable_v2_test.rb:481: warning: shadowing outer local variable - c
/home/runner/work/view_component/view_component/test/view_component/tasks_test.rb:16: warning: ambiguous first argument; put parentheses or a space even after `/' operator
Run options: --seed 12208

# Running:

/home/runner/work/view_component/view_component/lib/view_component/preview.rb:76: warning: shadowing outer local variable - preview_path

Other Information

I did not find how to fix those:

/home/runner/work/view_component/view_component/lib/view_component/polymorphic_slots.rb:41: warning: method redefined; discarding old header
/home/runner/work/view_component/view_component/lib/view_component/polymorphic_slots.rb:41: warning: previous definition of header was here
/home/runner/work/view_component/view_component/lib/view_component/polymorphic_slots.rb:41: warning: method redefined; discarding old items
/home/runner/work/view_component/view_component/lib/view_component/polymorphic_slots.rb:41: warning: previous definition of items was here

I also took care of this:

The following cops were added to RuboCop, but are not configured. Please set Enabled to either `true` or `false` in your `.rubocop.yml` file.

Please also note that can also opt-in to new cops by default by adding this to your config:
  AllCops:
    NewCops: enable
Layout/SpaceBeforeBrackets: # (new in 1.7)
  Enabled: true
For more information: https://docs.rubocop.org/rubocop/versioning.html

[BlakeWilliams]

Thanks for cleaning those warnings up!

[Spone]

@elia should we merge this before #1277?

[elia]

@elia should we merge this before #1277?

@Spone sure! 🙌 I'll rebase once this is merged 👍