security/libsecret: fix build with clang 16

Clang 16 has a new error about incompatible function types, which shows
up when building security/libsecret:

  libsecret/test-vala-lang.p/test-vala-lang.c:1166:51: error: incompatible function pointer types passing 'void (gpointer)' (aka 'void (void *)') to parameter of type 'GTestDataFunc' (aka 'void (*)(const void *)') [-Wincompatible-function-pointer-types]
          g_test_add_data_func ("/vala/lookup/sync", NULL, _test_lookup_sync_gtest_data_func);
                                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/local/include/glib-2.0/glib/gtestutils.h:337:58: note: passing argument to parameter 'test_func' here
                                           GTestDataFunc   test_func);
                                                           ^

Since the errors all occur in vala-generated code, it does not make
sense to patch the .c files. Suppress the warning instead.

PR:		271320
Approved by:	portmgr (build fix blanket)
MFH:		2023Q2

security/libsecret/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	libsecret
 PORTVERSION=	0.20.5
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	security gnome
 MASTER_SITES=	GNOME
 
@@ -15,7 +15,13 @@ BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}gi-docgen>0:textproc/py-gi-docgen@${PY_FLA
 LIB_DEPENDS=	libgcrypt.so:security/libgcrypt \
 		libgpg-error.so:security/libgpg-error
 
-USES=		gnome meson pkgconfig python:3.8+ tar:xz vala:build
+USES=		compiler gnome meson pkgconfig python:3.8+ tar:xz vala:build
 USE_GNOME=	glib20 intltool introspection:build libxslt:build
 
-.include <bsd.port.mk>
+.include <bsd.port.pre.mk>
+
+.if ${COMPILER_TYPE} == clang
+CFLAGS+=	-Wno-incompatible-function-pointer-types
+.endif
+
+.include <bsd.port.post.mk>