community/{pipewire,wireplumber}: Disable lto on armv7 and armhf
It makes some test fail, indicating pretty bad brokenness.
This was discovered while testing a downstream fork in pmOS. Given that Pipewire becomes increasingly important, making it work correctly on these platforms is probably a worthy goal.
I couldn't test this on real hardware as I don't have any respective devices - but regressions apart from slightly worse performance is very unlikely.