Update Mailchimp API key validity check (#49076)

Co-authored-by: mc <[email protected]>

Author: janellaco

data/secret-scanning.yml

@@ -1578,7 +1578,7 @@
   isPublic: true
   isPrivateWithGhas: true
   hasPushProtection: false
-  hasValidityCheck: false
+  hasValidityCheck: '{% ifversion fpt or ghes %}false{% else %}true{% endif %}'
 
 - provider: 'Mailchimp'
   supportedSecret: 'Mandrill API Key'