Add a retry counter

[lazka]

We should try to build things ~3 times until we give up.. maybe with a delay between. Sometimes there are network issues...

[lazka]

Alternative: Split the build into two steps, where the first one can be retried a few times:

retry makepkg-mingw --cleanbuild --nobuild # downloads and extracts
makepkg-mingw ... --noextract # use exisiting src dir

edit: Downside is that makedepends are missing, unless we install/uninstall all of them.. so maybe not.

[lazka]

Current status: There is now an action which makes deleting the failed state easier..