Upgrade ubuntu version for CI formatting checks
Upgrade ubuntu version for CI formatting checks

Ubuntu 18.04 is deprecated and will be removed soon.

Signed-off-by: Patrick Avery <743342299f279e7a8c3ff5eb40671fce3e95f13a@kitware.com>

OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz