Update rspec-rails requirement from ~> 6.0 to ~> 7.1

Updates the requirements on [rspec-rails](https://github.com/rspec/rspec-rails) to permit the latest version.
- [Changelog](https://github.com/rspec/rspec-rails/blob/main/Changelog.md)
- [Commits](rspec/rspec-rails@v6.0.0...v7.1.1)

---
updated-dependencies:
- dependency-name: rspec-rails
  dependency-version: 7.1.1
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

publify_textfilter_code.gemspec

@@ -22,7 +22,7 @@ Gem::Specification.new do |s|
   s.add_dependency "htmlentities", "~> 4.3"
   s.add_dependency "publify_core", "~> 10.0.0"
 
-  s.add_development_dependency "rspec-rails", "~> 6.0"
+  s.add_development_dependency "rspec-rails", "~> 7.1"
   s.add_development_dependency "rubocop", "~> 1.75.6"
   s.add_development_dependency "rubocop-performance", "~> 1.23.1"
   s.add_development_dependency "rubocop-rails", "~> 2.32.0"