github actions: Upgrade Python to 3.8.6 and yamllint to 1.25
github actions: Upgrade Python to 3.8.6 and yamllint to 1.25

Signed-off-by: Bryan Gurney <94498243b15882748b18aec9e6dc02da713818c8@redhat.com>

stratis-storage/stratis-cli,stratis-storage/stratis-cli