fix: remove useless call get_collection in rename_collection

Author: matthv

packages/forest_admin_datasource_customizer/lib/forest_admin_datasource_customizer/decorators/rename_collection/rename_collection_datasource_decorator.rb

@@ -47,9 +47,6 @@ def rename_collections(renames)
         end
 
         def rename_collection(current_name, new_name)
-          # Check collection exists
-          get_collection(current_name)
-
           return unless current_name != new_name
 
           # Check new name is not already used

packages/forest_admin_datasource_customizer/spec/lib/forest_admin_datasource_customizer/decorators/rename_collection/rename_collection_datasource_decorator_spec.rb

@@ -111,15 +111,6 @@ module RenameCollection
               )
             end
 
-            it 'raise an error if the given old name does not exist' do
-              expect do
-                @datasource.rename_collection('doesNotExist', 'book')
-              end.to raise_error(
-                Exceptions::ForestException,
-                'Collection doesNotExist not found.'
-              )
-            end
-
             it 'change the foreign collection when it is a many to many' do
               @datasource.rename_collection('library_book', 'renamed_library_book')
               @datasource.rename_collection('book', 'renamed_book')