This will be used to build our image as well as tools that need to go
into this image.
Notable changes from Buster:
* Python 2/pip2 module installations have been removed, since nothing
besides the main Python 2 binary (and virtualenv support) is now
available through Bullseye.
* In the cases where both the main library package and the development
package are being installed, now, only the dev package is specified. The
main library is typically marked as a dependency of the dev package.
This reduces the number of changes we have to make as SONAMEs change.
Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>