tools/automake: bump to 1.16.5

Automake releases 1.16.2 to 1.16.5 are major releases,
the two before are minor releases.

The first patch needed rewriting, some lines moved
to be consistent with the same change upstream in other files.
This also simplifies the patch.

Second patch refreshed.

Links to changelogs in order, oldest to newest.

Link: https://lists.gnu.org/archive/html/info-gnu/2018-02/msg00008.html
Link: https://lists.gnu.org/archive/html/info-gnu/2018-03/msg00002.html
Link: https://lists.gnu.org/archive/html/info-gnu/2020-03/msg00009.html
Link: https://lists.gnu.org/archive/html/info-gnu/2020-11/msg00005.html
Link: https://lists.gnu.org/archive/html/info-gnu/2021-07/msg00013.html
Link: https://lists.gnu.org/archive/html/info-gnu/2021-10/msg00000.html
Signed-off-by: Michael Pratt <mcpratt@pm.me>

tools/automake/patches/100-aclocal-skip-not-existing-directories.patch

@@ -1,6 +1,6 @@
 --- a/bin/aclocal.in
 +++ b/bin/aclocal.in
-@@ -356,6 +356,12 @@ sub scan_m4_dirs ($$@)
+@@ -371,6 +371,12 @@ sub scan_m4_dirs ($$@)
  
    foreach my $m4dir (@dirlist)
      {