build(deps): update stripe requirement from ~> 11.3.0 to ~> 13.0.0

Updates the requirements on [stripe](https://github.com/stripe/stripe-ruby) to permit the latest version.
- [Release notes](https://github.com/stripe/stripe-ruby/releases)
- [Changelog](https://github.com/stripe/stripe-ruby/blob/master/CHANGELOG.md)
- [Commits](stripe/stripe-ruby@v11.3.0...v13.0.0)

---
updated-dependencies:
- dependency-name: stripe
  dependency-type: direct:production
...

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

Author: dependabot[bot]

server/ruby/Gemfile

@@ -3,5 +3,5 @@ source 'https://rubygems.org/'
 gem 'dotenv'
 gem "rackup"
 gem 'sinatra'
-gem 'stripe', '~> 11.3.0'
+gem 'stripe', '~> 13.0.0'
 gem 'webrick'