Bump rubocop-performance from 1.19.1 to 1.20.2

Note we're removing the Performance/StringIdentifierArgument rule
because now it also replaces methods in interpolation, and we don't
particularly prefer using `send(:"#{method}_name")` over
`send("#{method}_name)`. We actually use the latter about two thirds of
the time.

We'll add this rule again if it ever offers the option to ignore the
cases where interpolation is used, although it's highly doubtful that'll
ever happen because this rule is meant for (insignificant) performance
gains and not for code clarity.

Bumps [rubocop-performance](https://github.com/rubocop/rubocop-performance) from 1.19.1 to 1.20.2.
- [Release notes](https://github.com/rubocop/rubocop-performance/releases)
- [Changelog](https://github.com/rubocop/rubocop-performance/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop-performance/compare/v1.19.1...v1.20.2)

---
updated-dependencies:
- dependency-name: rubocop-performance
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -107,7 +107,7 @@ group :development do
   gem "rubocop", "~> 1.56.4", require: false
   gem "rubocop-capybara", "~> 2.20.0", require: false
   gem "rubocop-factory_bot", "~> 2.25.1", require: false
-  gem "rubocop-performance", "~> 1.19.1", require: false
+  gem "rubocop-performance", "~> 1.20.2", require: false
   gem "rubocop-rails", "~> 2.23.1", require: false
   gem "rubocop-rspec", "~> 2.27.0", require: false
   gem "rvm1-capistrano3", "~> 1.4.0", require: false