Big Sur 11.3 + Xcode 12.5 + CLT

[rezwits]

After installing Big Sur 11.3,
if you proceed to Xcode 12.5,
after that is done,
BEFORE using xcode-select --install
going to Brew and upgrading/updating
go BACK to Software Update and install CLTs
then go back to `brew upgrade`

If not you'll probably get the warning...