Update webmock requirement from ~> 3.3.0 to ~> 3.7.4

Updates the requirements on [webmock](https://github.com/bblimke/webmock) to permit the latest version.
- [Release notes](https://github.com/bblimke/webmock/releases)
- [Changelog](https://github.com/bblimke/webmock/blob/master/CHANGELOG.md)
- [Commits](bblimke/webmock@v3.3.0...v3.7.4)

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

alchemy-api-rb.gemspec

@@ -26,7 +26,7 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'rake',                '~> 10.3.0'
   gem.add_development_dependency 'minitest-reporters',  '~> 1.0.0'
   gem.add_development_dependency 'vcr',                 '~> 2.9.2'
-  gem.add_development_dependency 'webmock',             '~> 3.3.0'
+  gem.add_development_dependency 'webmock',             '~> 3.7.4'
   gem.add_development_dependency 'coveralls',           '~> 0.7.0'
   gem.add_development_dependency 'rubocop',             '~> 0.52.1'
 end