Big Bang Bot: Update CODEOWNERS

Action	User	Reason
Remove	@snaq11092	Employment dates no longer active
Remove	@dax.mcdonald	Username is not present in either team or contributor whitelist.
Add	@daxmc99	User added from team charter mission team manifest

These changes were automatically generated based on the state stored in the team charter mission team manifest. If these changes are not expected, please refer to updating team charter manifest.