lm-sensors: Migrate from Linuxbrew/homebrew-extra tap
lm-sensors: Migrate from Linuxbrew/homebrew-extra tap

- I've added a `--help` text check as a test to appease `brew audit
  --strict` - we can revisit this later. I would have done an actual
  test, but I didn't know what CI would output as against my local
  machine.
- I also renamed this formula `lm-sensors` from `lm_sensors` as
  the source repo is hyphenated.
- This was added to Linuxbrew/homebrew-extra, but that repo is less
  discoverable than this one, requires enother `brew tap` command,
  and we're gradually deprecating the Linuxbrew organisation.
- This is tagged with `linuxbrew` so that it's visibly Linux-only.

Closes #15027.

Signed-off-by: Issy Long <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@issyl0.co.uk>

LinuxbrewTestBot/homebrew-core,Linuxbrew/homebrew-core,maxim-belkin/homebrew-core,Linuxbrew/homebrew-core,LinuxbrewTestBot/homebrew-core,rwhogg/homebrew-core,rwhogg/homebrew-core,maxim-belkin/homebrew-core