Retire the bn_rand_interval() test

This test was never particularly useful. An upcoming API change for
the internal bn_rand_interval() API would require some adjustments.
It's not worth it.

Author: tb

src/regress/lib/libcrypto/bn/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.34 2023/07/06 15:08:54 tb Exp $
+#	$OpenBSD: Makefile,v 1.35 2023/08/03 18:44:31 tb Exp $
 
 PROGS +=	bn_add_sub
 PROGS +=	bn_cmp
@@ -13,7 +13,6 @@ PROGS +=	bn_mont
 PROGS +=	bn_mul_div
 PROGS +=	bn_primes
 PROGS +=	bn_print
-PROGS +=	bn_rand_interval
 PROGS +=	bn_shift
 PROGS +=	bn_test
 PROGS +=	bn_to_string
@@ -24,7 +23,6 @@ STATIC_LINK +=	bn_gcd
 STATIC_LINK +=	bn_isqrt
 STATIC_LINK +=	bn_mod_exp
 STATIC_LINK +=	bn_print
-STATIC_LINK +=	bn_rand_interval
 STATIC_LINK +=	bn_test
 
 LDADD =		-lcrypto