fix a performance issue with dependent params

Fixes #2100

The reason was in `ActiveSupport::HashWithIndifferentAccess`, it
is super expensive.

When users use `Grape::Extensions::ActiveSupport::HashWithIndifferentAccess::ParamBuilder`
or `Grape::Extensions::Hashie::Mash::ParamBuilder` as a parameter builder
there is no change. However, users who use `Grape::Extensions::Hash::ParamBuilder`
must make sure an attribute to be dependent on must be a symbol.

    given :matrix do
      # block here
    end

CHANGELOG.md

@@ -7,6 +7,7 @@
 #### Fixes
 
 * Your contribution here.
+* [#](https://github.com/ruby-grape/grape/pull/): Fix performance issues with dependent params - [@dnesteryuk](https://github.com/dnesteryuk).
 * [#2126](https://github.com/ruby-grape/grape/pull/2126): Fix warnings about redefined attribute accessors in `AttributeTranslator` - [@samsonjs](https://github.com/samsonjs).
 * [#2121](https://github.com/ruby-grape/grape/pull/2121): Fix 2.7 deprecation warning in validator_factory - [@Legogris](https://github.com/Legogris).
 * [#2115](https://github.com/ruby-grape/grape/pull/2115): Fix declared_params regression with multiple allowed types - [@stanhu](https://github.com/stanhu).

lib/grape/validations/params_scope.rb

@@ -62,7 +62,6 @@ def meets_dependency?(params, request_params)
 
         return params.any? { |param| meets_dependency?(param, request_params) } if params.is_a?(Array)
         return false unless params.respond_to?(:with_indifferent_access)
-        params = params.with_indifferent_access
 
         @dependent_on.each do |dependency|
           if dependency.is_a?(Hash)