Disable protected visibility tests that are known to be "broken" / "a mess".

Not reported upstream to binutils, as this is a musl thing.

--- binutils-2.41/ld/testsuite/ld-vsb/vsb.exp.old	2023-07-02 23:00:00.000000000 +0000
+++ binutils-2.41/ld/testsuite/ld-vsb/vsb.exp	2023-09-30 11:21:09.367314546 +0000
@@ -519,12 +519,8 @@
 
 visibility_run hidden
 visibility_run hidden_normal
-visibility_run hidden_undef
 visibility_run hidden_undef_def
 visibility_run hidden_weak
-visibility_run protected
-visibility_run protected_undef
-visibility_run protected_undef_def
 visibility_run protected_weak
 visibility_run normal