Add meson

Meson <0.51.0 doesn't support building libraries with Cargo due to custom_target only producing executables.

Cargo is needed to unlock access to packages from crates.io, which would greatly help clean up squeekboard.
1 job for cargo in 21 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #132766
librem5
build-native

00:00:21