remove unnecessary hashie version limit

A ceiling was originally introduced “just in case” before hashie 4.0 (11 years ago: f54ad72, see also e73fa18), and then only the value has been updated (to 5.x and 6.x). This means unnecessary difficulties when a new major version of hashie comes out without any gains, so let’s just drop it.

Author: razumau

zendesk_api.gemspec

@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
 
   s.add_runtime_dependency "faraday", "> 2.0.0"
   s.add_runtime_dependency "faraday-multipart"
-  s.add_runtime_dependency "hashie", ">= 3.5.2", "< 6.0.0"
+  s.add_runtime_dependency "hashie", ">= 3.5.2"
   s.add_runtime_dependency "inflection"
   s.add_runtime_dependency "multipart-post", "~> 2.0"
   s.add_runtime_dependency "mini_mime"