Update rubocop requirement from ~> 1.65.1 to ~> 1.75.6

Updates the requirements on [rubocop](https://github.com/rubocop/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.65.1...v1.75.6)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-version: 1.75.6
  dependency-type: direct:development
...

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

Author: dependabot[bot]

publify_textfilter_code.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
   s.add_dependency "publify_core", "~> 10.0.0"
 
   s.add_development_dependency "rspec-rails", "~> 6.0"
-  s.add_development_dependency "rubocop", "~> 1.65.1"
+  s.add_development_dependency "rubocop", "~> 1.75.6"
   s.add_development_dependency "rubocop-performance", "~> 1.21.1"
   s.add_development_dependency "rubocop-rails", "~> 2.25.0"
   s.add_development_dependency "rubocop-rspec", "~> 3.4.0"