fix(crystal): remove dead code

Author: n-rodriguez

modules/openapi-generator/src/main/resources/crystal/spec_helper.mustache

@@ -2,14 +2,4 @@
 
 # load modules
 require "spectator"
-require "json"
-require "time"
 require "../src/{{{shardName}}}"
-
-def assert_compilation_error(path : String, message : String) : Nil
-  buffer = IO::Memory.new
-  result = Process.run("crystal", ["run", "--no-color", "--no-codegen", path], error: buffer)
-  result.success?.should be_false
-  buffer.to_s.should contain message
-  buffer.close
-end

samples/client/petstore/crystal/spec/spec_helper.cr

@@ -10,14 +10,4 @@
 
 # load modules
 require "spectator"
-require "json"
-require "time"
 require "../src/petstore"
-
-def assert_compilation_error(path : String, message : String) : Nil
-  buffer = IO::Memory.new
-  result = Process.run("crystal", ["run", "--no-color", "--no-codegen", path], error: buffer)
-  result.success?.should be_false
-  buffer.to_s.should contain message
-  buffer.close
-end