Ubuntu 20.04 release depends on wrong `libc6` version.

[reitermarkus]

I tried installing the git-interactive-rebase-tool-2.4.1-ubuntu-20.04_amd64.deb release package, which fails with

The following packages have unmet dependencies:
 git-interactive-rebase-tool : Depends: libc6 (>= 2.34) but 2.31-0ubuntu9.16 is to be installed

The latest libc6 on Ubuntu 20.04 is 2.31: https://launchpad.net/ubuntu/focal/+package/libc6

[MitMaro]

This is due to rust-lang/rust#57497, but I thought the usage of Cross should have fixed it, so it may also be cross-rs/cross#724.

I'll need to reproduce the problem outside the GitHub runners, as this should have used the libc from the target Ubuntu version, not the host runner.

[MitMaro]

As of #973, Linux builds are now using fully static binaries and should no longer depend on a dynamic version of libc.

I still need to do some verification of the binaries, just to ensure no mistakes, but the latest release should now install.