Fix cargo machete

[mxpv]

Something weird going on with cargo machete.
I've disabled it for now to get CI going and to unblock PRs merging, this requires some further investigation:

 Downloaded humantime v2.1.0
  Downloaded bstr v1.11.0
  Downloaded cargo-platform v0.1.9
  Downloaded encoding_rs v0.8.35
error: failed to compile `cargo-machete v0.7.0`, intermediate artifacts can be found at `/var/folders/5q/zcc7tkt11f13mhczs1yfd4qc0000gn/T/cargo-installD6miBw`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.

Caused by:
  package `cargo-platform v0.1.9` cannot be built because it requires rustc 1.78 or newer, while the currently active rustc version is 1.77.2
  Try re-running cargo install with `--locked`

https://github.com/containerd/rust-extensions/actions/runs/12145237311/job/33866410733

[jokemanfire]

looks like rust toolchain should update to 1.78?