update the mend (whitesource) config

[lemke-ethan]

https://docs.mend.io/bundle/community_tools/page/mend_bolt_for_github.html

[lemke-ethan]

• updated the mend config to match the docs.
• replaced the "Mend Security Check" status check on the main branch with "WhiteSource Security Check". the mend docs say to add the mend check, but there must be some issue on their end because it never completed and the WhiteSource check always ran and completed.