ci: Use renderdoc from debian
This one is harder than #3124 (closed) -- the current renderdoc package is monolithic and brings in QT for the gui, which we don't really want for our container. But building renderdoc is slow and we could avoid it: install the package, copy the 3 files we need out, uninstall.
debian bug for splitting the package: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=962718