meson: Explicitly add "check : false" to a couple instances of run_command

meson: Explicitly add "check : false" to a couple instances of run_command

In both cases there's code right after the execution to check the result and
give a proper message.

This gets rid of meson warning

```
WARNING: You should add the boolean check kwarg to the run_command call.
         It currently defaults to false,
         but it will default to true in future releases of meson.
         See also: https://github.com/mesonbuild/meson/issues/9300
```

Reviewed-by: Eric Engestrom <eric@igalia.com>
Reviewed-by: Yonggang Luo <luoyonggang@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23821>