fix: check for NoMethodError instead of NotImplementedError (#545)

[Pundit have recently
changed](varvet/pundit#776) to using
`NoMethodError`, which breaks our spec - the main benefit of this change
is that the new error extends from `StandardError` so in theory is
easier to catch; however, it seems the community is divided as aside
from the different superclass the existing error is more accurate since
`NoMethodError` is meant to be thrown when the class does not
`respond_to?` the method in question and that is not true.

I personally would like to keep using `NotImplementedError` though I'm
happy to change if someone does prove a real-world situation where it's
more burdson to catch (or that our error monitoring won't catch it), but
I feel that should be a separate conversation - so this PR is changing
it back to maintain our current status quo until such time that we do
decide to change.

variants/pundit/template.rb

@@ -8,6 +8,12 @@
 run "rails g pundit:install"
 run "rails g pundit:policy example"
 
+# Pundit uses NoMethodError which is easier to catch as it extends from StandardError,
+# but it's technically not correct as our class does respond to the method in question
+#
+# For now, we're just going to stick with the more traditional error for this situation
+gsub_file! "app/policies/application_policy.rb", "raise NoMethodError", "raise NotImplementedError"
+
 copy_file "spec/policies/example_policy_spec.rb", force: true
 copy_file "spec/policies/application_policy_spec.rb", force: true