It turned out to be a fairly small deal. For reference sake a brief write up of updating the Go runtime on my Ubuntu environment.
Find latest releases of Go at https://go.dev/dl/
There is a new one. I copy the link and then run:
Then installation is nothing more than:
sudo tar -C /usr/local –xzf go1.17.6.linux-amd64.tar.gz
Then I run go version again to check whether I now have the latest Go version – and I do (1.17.6).
Finally I remove the downloaded tar ball