Sysprof has moved to a new ABI which removes GLib from the capture library
so that GLib itself can link against sysprof-capture.

This bumps the library ABI so we can keep things coordinated between all
the new tracing layers in the stack.

This is an attempt to see how we can use sysprof data
in our tests to extract useful performance numbers.

Use it as a wrapper around any GTK+ process:

./testperf ./gtk4-widget-factory

Currently, it repeatedly runs the given commandline,
extracts the first css validation time from the resulting
syscap file, and prints out the min/max/avg of the runs
at the end.

This relies on the environment variable GTK_DEBUG_AUTO_QUIT
to cause the process to exit soon after launch.