update mise file with rust

[jaydeluca]

While running some of the mise commands in https://github.com/grafana/docker-otel-lgtm/blob/main/CONTRIBUTING.md, I encountered the error:

mise ERROR failed to install cargo:zizmor@1.6.0
mise ERROR failed to execute command: cargo install zizmor@1.6.0 --locked --root /Users/jay/.local/share/mise/installs/cargo-zizmor/1.6.0
mise ERROR No such file or directory (os error 2)

The issue was that I did not have rust installed, therefore I am adding it to the mise config to automatically install it.

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[zeitlinger]

thanks for the fix