Do not install pre-generated manpages.

Also remove redundant autotools stages.

Early manpages in autoconf 2.52-2.59 are removed from output.
Later ones are regenerated with help2man.

Fixes #182

sysa/automake-1.7/stage2.sh

@@ -1,21 +0,0 @@
-# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
-#
-# SPDX-License-Identifier: GPL-3.0-or-later
-
-src_prepare() {
-    rm -- configure Makefile.in */Makefile.in */*/Makefile.in aclocal.m4 automake.info*
-
-    autoreconf-2.54
-}
-
-src_configure() {
-    ./configure --prefix="${PREFIX}"
-}
-
-src_compile() {
-    make MAKEINFO=true
-}
-
-src_install() {
-    make install MAKEINFO=true DESTDIR="${DESTDIR}"
-}