Revert "compositor: add weston.ini option use-renderer-shadow"

This reverts commit 81ef6d0ab3.

This also removes a bit from "tests: ensure color-lcms plugin loads".

Use of the shadow buffer is determined automatically based on
color transformations by the previous commit
"gl-renderer: use shadow framebuffer automatically".

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

tests/color-manager-test.c

@@ -39,10 +39,7 @@ fixture_setup(struct weston_test_harness *harness)
 
 	weston_ini_setup(&setup,
 			 cfgln("[core]"),
-			 cfgln("color-management=true"),
-			 cfgln("[output]"),
-			 cfgln("name=headless"),
-			 cfgln("use-renderer-shadow=true"));
+			 cfgln("color-management=true"));
 
 	return weston_test_harness_execute_as_client(harness, &setup);
 }