Add support for `enum` datatype in schema.rb

key not found: :enum
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph/rails/schema.rb:50:in `fetch'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph/rails/schema.rb:50:in `block in process'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph/rails/schema.rb:46:in `each'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph/rails/schema.rb:46:in `map'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph/rails/schema.rb:46:in `process'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph-rails.rb:45:in `block in local'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph-rails.rb:60:in `run_feature'
/bundle/ruby/3.2.0/gems/solargraph-rails-1.1.0/lib/solargraph-rails.rb:45:in `local'