Bumped ruby version requirement to 3.0.0

Author: mohammed-io

diffcrypt.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
   spec.description   = 'Diffable encrypted configuration files that can be safely committed into a git repository'
   spec.homepage      = 'https://github.com/diffcrypt/diffcrypt-ruby'
   spec.license       = 'MIT'
-  spec.required_ruby_version = Gem::Requirement.new('>= 2.6.0')
+  spec.required_ruby_version = Gem::Requirement.new('>= 3.0.0')
 
   # spec.metadata["allowed_push_host"] = "TODO: Set to 'http://mygemserver.com'"