Update .rubocop_shopify_styleguide.yml (#11533)

I fixed the assigned issue #11527 by updating the file .rubocop_shopify_styleguide.yml.
I have removed IgnoredMethods: in line 67 and added AllowedMethods:
I have also removed IgnoredMethods: in line 417 and added AllowedMethods:

.rubocop_shopify_styleguide.yml

@@ -64,7 +64,7 @@ Style/BlockDelimiters:
   - let!
   - subject
   - watch
-  IgnoredMethods:
+  AllowedMethods:
   - lambda
   - proc
   - it
@@ -415,7 +415,7 @@ Layout/SpaceInsideStringInterpolation:
   - no_space
 
 Style/SymbolProc:
-  IgnoredMethods:
+  AllowedMethods:
   - respond_to
   - define_method