Update 'undefined local variable' error message

Ruby 3.3 changes the format slightly

Ruby <3.3:
> undefined local variable or method `generate_unhandled_error' for #<BeforeNotifyController

Ruby 3.3:
> undefined local variable or method `generate_unhandled_error' for an instance of BeforeNotifyController

features/rails_features/before_notify.feature

@@ -21,7 +21,7 @@ Scenario: Rails before_notify controller method works on unhandled errors
   And I wait to receive an error
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<BeforeNotifyController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )BeforeNotifyController"
   And the event "unhandled" is true
   And the event "app.type" equals "rails"
   And the event "metaData.request.url" ends with "/before_notify/unhandled"

features/rails_features/handled.feature

@@ -21,7 +21,7 @@ Scenario: Thrown handled NameError
   And I wait to receive an error
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<HandledController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )HandledController"
   And the event "unhandled" is false
   And the event "metaData.request.url" ends with "/handled/thrown"
   And the event "app.type" equals "rails"

features/rails_features/on_error.feature

@@ -22,7 +22,7 @@ Scenario: Rails on_error works on unhandled errors
   And I wait to receive an error
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<UnhandledController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )UnhandledController"
   And the event "unhandled" is true
   And the event "app.type" equals "rails"
   And the event "metaData.request.url" ends with "/unhandled/error"

features/rails_features/request.feature

@@ -8,7 +8,7 @@ Scenario: Request data is collected automatically
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the event "unhandled" is true
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<UnhandledController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )UnhandledController"
   And the event "app.type" equals "rails"
   And the event "metaData.request.clientIp" is not null
   And the event "metaData.request.headers.Host" is not null
@@ -33,7 +33,7 @@ Scenario: Request data can be modified in callbacks
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the event "unhandled" is true
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<UnhandledController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )UnhandledController"
   And the event "app.type" equals "rails"
   And the event "metaData.request.something" equals "hello"
   And the event "metaData.request.params.another_thing" equals "hi"

features/rails_features/unhandled.feature

@@ -8,7 +8,7 @@ Scenario: Unhandled RuntimeError
   Then the error is valid for the error reporting API version "4.0" for the "Ruby Bugsnag Notifier" notifier
   And the event "unhandled" is true
   And the exception "errorClass" equals "NameError"
-  And the exception "message" starts with "undefined local variable or method `generate_unhandled_error' for #<UnhandledController"
+  And the exception "message" matches "^undefined local variable or method `generate_unhandled_error' for (#<|an instance of )UnhandledController"
   And the event "app.type" equals "rails"
   And the event "metaData.request.url" ends with "/unhandled/error"
   And the event "severity" equals "error"