Remove dead constant MAX_RETRIES (#505)

Remove deadcode from lib/ruby_lsp/ruby_lsp_rails/runner_client.rb

Co-authored-by: shopify-codedb[bot] <shopify-codedb[bot]@users.noreply.github.com>

Author: shopify-codedb[bot]

lib/ruby_lsp/ruby_lsp_rails/runner_client.rb

@@ -46,8 +46,6 @@ class InitializationError < StandardError; end
       class IncompleteMessageError < StandardError; end
       class EmptyMessageError < StandardError; end
 
-      MAX_RETRIES = 5
-
       extend T::Sig
 
       sig { returns(String) }