fix: Gemfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-RACK-2848599

Author: snyk-bot

Gemfile

@@ -22,7 +22,7 @@ gem 'bootsnap', '>= 1.4.4', require: false
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
-  gem 'rspec-rails'
+  gem 'rspec-rails', '>= 8.0.0'
   gem 'dotenv-rails'
 end