configure: bump Meson to 1.9.0 for use with Rust

Meson 1.9.0 provides mixed linking of Rust and C objects.  As a side effect,
this also allows adding dependencies with "sources: ..." files to Rust crates
that use structured_sources().

It can also clean up up the meson.build files for Rust noticeably, but due
to an issue with doctests (see https://github.com/mesonbuild/meson/pull/14973)
that will have to wait for 1.9.1.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250908105005.2119297-3-pbonzini@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
5 files changed