etc: drop vestiges of obsolete DSA ssh host keys

It has been 8 years since DSA keys were disabled by default for
ssh/sshd, and 15 months since ssh-keygen -A belatedly stopped
generating DSA host keys.

ok semarie@ deraadt@

etc/changelist

@@ -1,4 +1,4 @@
-#	$OpenBSD: changelist,v 1.136 2023/04/24 16:36:54 kn Exp $
+#	$OpenBSD: changelist,v 1.137 2023/09/19 15:02:54 naddy Exp $
 #
 # List of files which the security script backs up and checks
 # for modifications.
@@ -126,8 +126,6 @@
 +/etc/soii.key
 +/etc/spwd.db
 /etc/ssh/ssh_config
-+/etc/ssh/ssh_host_dsa_key
-/etc/ssh/ssh_host_dsa_key.pub
 +/etc/ssh/ssh_host_ecdsa_key
 /etc/ssh/ssh_host_ecdsa_key.pub
 +/etc/ssh/ssh_host_ed25519_key

etc/mtree/special

@@ -1,4 +1,4 @@
-#	$OpenBSD: special,v 1.128 2022/05/12 22:13:06 sthen Exp $
+#	$OpenBSD: special,v 1.129 2023/09/19 15:02:55 naddy Exp $
 #
 # Hand-crafted mtree specification for the dangerous files.
 #
@@ -101,8 +101,6 @@ soii.key	type=file mode=0600 uname=root gname=wheel optional
 spwd.db		type=file mode=0640 uname=root gname=_shadow
 ssh		type=dir mode=0755 uname=root gname=wheel optional
 ssh_config	type=file mode=0644 uname=root gname=wheel
-ssh_host_dsa_key	type=file mode=0600 uname=root gname=wheel optional
-ssh_host_dsa_key.pub	type=file mode=0644 uname=root gname=wheel optional
 ssh_host_ecdsa_key	type=file mode=0600 uname=root gname=wheel optional
 ssh_host_ecdsa_key.pub	type=file mode=0644 uname=root gname=wheel optional
 ssh_host_ed25519_key	type=file mode=0600 uname=root gname=wheel optional