Upstream bundles python deps and uses same interpreter as meson,
but we don't and need this to use the eclass' python3 instead.

https://bugs.gentoo.org/731728
--- a/meson.build
+++ b/meson.build
@@ -323,3 +323,3 @@
 thirdparty = meson.project_source_root()/'3rdparty'
-python = import('python').find_installation()
+python = import('python').find_installation('python3')
 python_env = environment()