web: set noopener and noreferrer on all external links (#10304)

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

web/src/admin/property-mappings/PropertyMappingNotification.ts

@@ -62,6 +62,7 @@ export class PropertyMappingNotification extends ModelForm<NotificationWebhookMa
                     ${msg("Expression using Python.")}
                     <a
                         target="_blank"
+                        rel="noopener noreferrer"
                         href="${docLink("/docs/property-mappings/expression?utm_source=authentik")}"
                     >
                         ${msg("See documentation for a list of all variables.")}