charter: Update DEI Advisor, remove auxiliary status
    
    This commit changes the Fedora Council charter to use updated language
    about the Diversity, Equity, & Inclusion Advisor. In 2017, the role was
    changed to "Diversity & Inclusion Team Representative", but in its real
    function, this was not how the role was utilized in the Council. For
    some time, the DEI Team documentation reflects the role as "DEI Advisor"
    while the official Council charter does not reflect this. So, the main
    change in this is updating the language to match what the DEI Team
    includes as role documentation for the DEI Advisor to the Council.
    
    Additionally, the DEI Advisor is now moved from an auxiliary seat to a
    full, voting member of the Fedora Council. This is a step as a whole to
    retire the auxiliary seats and give every member of the Council an equal
    voice and impact in voting and decisions. In function, this is how the
    Council already works, but our charter is not reflective of this and
    technically the charter is the ultimate truth.
    
    This follows an in-person conversation with @mattdm, and by opening a
    Pull Request for this change, requires a Council vote to update the
    charter.
    
    Signed-off-by: Justin W. Flory (he/him) <jwf@redhat.com>