[Runner] Fix glibc version of x86 architectures

[giordano]

No description provided.

[giordano]

  Installing cargo_build v0.1.0 (/usr/share/testsuite/rust/cargo_build)
error: failed to compile `cargo_build v0.1.0 (/usr/share/testsuite/rust/cargo_build)`, intermediate artifacts can be found at `/usr/share/testsuite/rust/cargo_build/target`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.

Caused by:
  failed to create directory `/usr/share/testsuite/rust/cargo_build/target`

Caused by:
  Cross-device link (os error 18)
make[1]: *** [Makefile:7: /tmp/testsuite/x86_64-linux-gnu/rust/cargo_build/cargo_build] Error 101
make: *** [Makefile:48: install-project-rust-cargo_build] Error 2
make: *** Waiting for unfinished jobs....

I don't really have the strength to chase down this kind of issues now, but I presume this is due to using a newer version of the Ubuntu images on GitHub Actions runners.