Oh well I tried today, and it seems that getting the more recent version of ggplot2 requires a newer version of rlang.
So I also tried to remove the older rlang and replace with a newer, but I couldn't make that work either.
And in the process I seem to have completely removed ggplot2 from my system, and I've tried to reinstall but it doesn't seem to be working:
Warning in install.packages :
installation of package ‘ggplot2’ had non-zero exit status
The downloaded source packages are in
Unfortunately I don't know what that means!