libweston: bump major version to 10

Commit 32a5acde5b
"tests: add mechanism to change Weston's behavior when running certain
tests"

added a new field to struct weston_compositor. Since that struct is
still in the public header, this breaks ABI. Bump the library version
accordingly.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

meson.build

@@ -10,7 +10,7 @@ project('weston',
 	license: 'MIT/Expat',
 )
 
-libweston_major = 9
+libweston_major = 10
 
 # libweston_revision is manufactured to follow the autotools build's
 # library file naming, thanks to libtool