Release 0.9

Todo:

• merge !445 (closed) (vrend: match Mesa gbm headers)
• merge !438 (merged) (perf: add scripts for performance analysis with perf)
• merge !447 (merged) (meson: Use meson endianess and cpu_family checks)
• merge !432 (merged) (add virgl_renderer_context_with_capsets (and vtest changes)

@gurchetansingh @olv any other things we should land before cutting a new release?