kmc-solid: Fix SOLID target This PR is a follow-up for #86191 and necessary to make the [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets actually usable. - Bumps `libc` to 0.2.106, which includes <https://github.com/rust-lang/libc/pull/2227>. - Applies the change made by #89324 to this target's target-specific code.