testsuite: Fix up vector-subaccess-1.C test for ia32 [PR89224]

The test FAILs on i686-linux due to
.../gcc/testsuite/g++.dg/torture/vector-subaccess-1.C:16:6: warning: SSE vector argument without SSE enabled changes the ABI [-Wpsabi]
excess warnings.

This fixes it by adding -Wno-psabi, like commonly done in other tests.

2024-05-09  Jakub Jelinek  <jakub@redhat.com>

	PR c++/89224
	* g++.dg/torture/vector-subaccess-1.C: Add -Wno-psabi as additional
	options.