Rustup missing on macOS-14-ARM runners

[SpikeHD]

Describe the bug The rustup utility, described as available in macOS 14 runners (and which is available in previous runners) here, is not present.

To Reproduce Steps to reproduce the behavior:

1. Create job with runs-on: macos-14-arm or runs-on: macos-latest
2. Have the job use a rustup command (such as rustup target add x86_64-apple-darwin)
3. Job will fail with rustup: command not found

Expected behavior rustup is available and works as expected.

Runner Version and Platform

Version of your runner? 20240422.3

OS of the machine running the runner? macOS 14

What's not working?

Failing job (macOS-14-ARM)	Succeeding job (macOS-13)

Job Log Output

> Run rustup target add x86_64-apple-darwin
  rustup target add x86_64-apple-darwin
  shell: /bin/bash -e {0}
/Users/runner/work/_temp/31cbddd0-8ace-4fa0-ac09-9cd3620e06a9.sh: line 1: rustup: command not found
Error: Process completed with exit code 127.