Enhancement: Replace the github action rust toolchain version to 1.81

[zong-zhe]

Enhancement

Currently, because the rust toolchain 1.81 environment is not compatible with the contents of the KCL code repository https://github.com/kcl-lang/kcl, we still compile some of the SDK with version 1.79 in the 0.11.0 release. And the cargo.lock file fixes the rust tripartite dependency home to version 0.5.9, because newer versions of the home require version 1.81 of the rust toolchain.

Take C SDK as an example, I manually fixed the version of home.

lib/c/Cargo.lock

Line 1233 in 7dac2f3

name = "home"

This will be fixed in future releases.

cc @He1pa