patch: Only install packages whose dependencies we can satisfy

In Tails 6.3, libc6 is installed in a different version than in Tails
6.2. I have libc6-dbg in my packages directory, which has a dependency
on the libc6 package of the same version. So I could only choose
between installing the version which can be installed on Tails 6.2 or
the one which can be installed on Tails 6.3.

With this commit, I can put both versions in the packages directory and
the install-packages script automatically chooses the one whose
dependencies can be satisfied.