…t.yml (#865)

Related to #863 and [this
comment](#862 (comment)):

> Having a similar problem since we had this line in our
`.overcommit.yml`:
> 
> ```yaml
> gemfile: Gemfile # enforce bundled version of overcommit
> ```
>
> And now overcommit doesn't strip out the inline comment, resulting in
this weird looking error message:
>
> ```
> Problem loading 'Gemfile # enforce bundled version of overcommit':
/path/to/project/Gemfile # enforce bundled version of overcommit not
found
> ```

I think adding support for comments in the `gemfile:` regexp is likely
overkill and may still not be enough when the next person tries to use
yet another YAML feature in that line, but perhaps this little warning
would help someone else avoid tripping.

Running `overcommit` with the `--diff` flag results in errors for
version `0.67.0`.

```sh
bundle exec overcommit --diff HEAD
```

It results on the following:

```ruby
Running pre-commit hooks
Check for case-insensitivity conflicts................[CaseConflicts] FAILED
Hook raised unexpected error
uninitialized constant Overcommit::Hook::PreCommit::CaseConflicts::Set

      repo_files = Set.new(applicable_files)
                   ^^^
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook/pre_commit/case_conflicts.rb:8:in `run'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook/base.rb:47:in `block in run_and_transform'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/utils.rb:260:in `with_environment'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook/base.rb:47:in `run_and_transform'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:162:in `run_hook'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:98:in `block in consume'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:94:in `loop'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:94:in `consume'
Analyze with RuboCop........................................[RuboCop] FAILED
Hook raised unexpected error
uninitialized constant Overcommit::GitRepo::Set

      lines = Set.new
              ^^^
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/git_repo.rb:69:in `extract_modified_lines'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_context/diff.rb:17:in `modified_lines_in_file'
/nix/store/0sj7d3r1kf95f27028j93j0sx3v6p1kw-ruby-3.1.6/lib/ruby/3.1.0/forwardable.rb:238:in `modified_lines_in_file'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:145:in `message_on_modified_line?'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:138:in `block in remove_ignored_messages'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:138:in `select'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:138:in `remove_ignored_messages'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:45:in `handle_modified_lines'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/message_processor.rb:39:in `hook_result'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook/base.rb:263:in `process_hook_return_value'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook/base.rb:48:in `run_and_transform'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:162:in `run_hook'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:98:in `block in consume'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:94:in `loop'
.bundle/ruby/3.1.0/gems/overcommit-0.67.0/lib/overcommit/hook_runner.rb:94:in `consume'

✗ One or more pre-commit hooks failed
```

The problems are fixed once `set` is required in the context that the
sub command is run.

`run_all.rb` also requires `set` where the module is
[defined](https://github.com/sds/overcommit/blob/main/lib/overcommit/hook_context/run_all.rb#L3).