Don't do SIGILL capability detection on Apple Silicon

Fixes #20753

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from #21261)

crypto/armcap.c

@@ -362,7 +362,7 @@ void OPENSSL_cpuid_setup(void)
         }
 #  endif
     }
-#  ifdef __aarch64__
+#  if defined(__aarch64__) && !defined(__APPLE__)
     if (sigsetjmp(ill_jmp, 1) == 0) {
         _armv8_sve_probe();
         OPENSSL_armcap_P |= ARMV8_SVE;