Update autotools.

Author: schweikert

CHANGELOG.md

@@ -40,6 +40,9 @@ fping 5.5-rc1 (2025-12-21)
 - GitHub Actions fixes (thanks @gsnw-sebast)
 - Fix measurement of time for timed reports (-Q) to start after DNS name
   resolution.
+- Updated autoconf from 2.71 to 2.72
+- Updated automake from 1.16.5 to 1.18.1
+- Updated libtool from 2.4.6 to 2.5.4
 
 fping 5.4 (2025-04-19)
 ======================

ci/build-1-autotools.sh

@@ -7,9 +7,9 @@ if [[ "$OSTYPE" == "darwin"* ]]; then
     exit 0
 fi
 
-AUTOCONF=https://ftpmirror.gnu.org/autoconf/autoconf-2.71.tar.gz
-AUTOMAKE=https://ftpmirror.gnu.org/automake/automake-1.16.5.tar.gz
-LIBTOOL=https://ftpmirror.gnu.org/libtool/libtool-2.4.6.tar.gz
+AUTOCONF=https://ftpmirror.gnu.org/autoconf/autoconf-2.72.tar.gz
+AUTOMAKE=https://ftpmirror.gnu.org/automake/automake-1.18.1.tar.gz
+LIBTOOL=https://ftpmirror.gnu.org/libtool/libtool-2.5.4.tar.gz
 PREFIX=$(pwd)/ci/build
 PATH=$(pwd)/ci/build/bin:$PATH