meson: fix deprecation warnings

[acsezen]

Summary

• add explicit check arguments to run_command() calls
• replace deprecated meson.source_root() with meson.project_source_root()
• raise the declared minimum Meson version to 0.56 to match the APIs already in use

Testing

• meson setup build-pr-check .

[jnovy]

@acsezen Thanks for this PR - would you mind to sign-off your commit?

[kolyshkin]

@acsezen can you please rebase (git pull --rebase origin main) and sign-off (git commit --amend -s) this commit?

[packit-as-a-service]

Ephemeral COPR build failed. @containers/packit-build please check.

[kolyshkin]

Nothing here (on GH CI) uses meson, so I tested this locally by building via meson. It works fine and removes a few meson warnings that were present before.

@acsezen can you please rebase (git pull --rebase origin main) and sign-off (git commit --amend -s) this commit?

Nevermind, let me carry this in #670