Deb: Clean away deprecated autobake modifications

The current debian/control file and other packaging of 10.5 targets the
latest Debian unstable. In autobake-deb.sh there are automatic build
adaptations for older Debian/Ubuntu releases.

Some adaptations were for Debian versions prior to Jessie and Ubuntu
versions prior to Trusty. Those distro releases are no longer supported
anyway, so these should be cleaned away now in the 10.5 release cycle.

Summary:
- Debian Jessie has libcrack2 release 2.9.2-1, no need to have adaptations
  for any older environments
- Debian Jessie has libpcre3-dev release 2:8.35-3.3, no need to consider
  older versions
- Systemd has been available since Debian Jessie, no need to consider
  that a Debian/Ubuntu environment would not have it available
  adaptations for environments for anything older

debian/autobake-deb.sh

@@ -42,36 +42,6 @@ GCCVERSION=$(gcc -dumpfullversion -dumpversion | sed -e 's/\.\([0-9][0-9]\)/\1/g
 # Debian policy and targeting Debian Sid. Then case-by-case run in autobake-deb.sh
 # tests for backwards compatibility and strip away parts on older builders.
 
-# If libcrack2 (>= 2.9.0) is not available (before Debian Jessie and Ubuntu Trusty)
-# clean away the cracklib stanzas so the package can build without them.
-if ! apt-cache madison libcrack2-dev | grep 'libcrack2-dev *| *2\.9' >/dev/null 2>&1
-then
-  sed '/libcrack2-dev/d' -i debian/control
-  sed '/Package: mariadb-plugin-cracklib/,/^$/d' -i debian/control
-fi
-
-# If libpcre3-dev (>= 2:8.35-3.2~) is not available (before Debian Jessie or Ubuntu Wily)
-# clean away the PCRE3 stanzas so the package can build without them.
-# Update check when version 2:8.40 or newer is available.
-if ! apt-cache madison libpcre3-dev | grep 'libpcre3-dev *| *2:8\.3[2-9]' >/dev/null 2>&1
-then
-  sed '/libpcre3-dev/d' -i debian/control
-fi
-
-# If libsystemd-dev is not available (before Debian Jessie or Ubuntu Wily)
-# clean away the systemd stanzas so the package can build without them.
-if ! apt-cache madison libsystemd-dev | grep 'libsystemd-dev' >/dev/null 2>&1
-then
-  sed '/dh-systemd/d' -i debian/control
-  sed '/libsystemd-dev/d' -i debian/control
-  sed 's/ --with systemd//' -i debian/rules
-  sed '/systemd/d' -i debian/rules
-  sed '/\.service/d' -i debian/rules
-  sed '/galera_new_cluster/d' -i debian/mariadb-server-10.5.install
-  sed '/galera_recovery/d' -i debian/mariadb-server-10.5.install
-  sed '/mariadb-service-convert/d' -i debian/mariadb-server-10.5.install
-fi
-
 # If libzstd-dev is not available (before Debian Stretch and Ubuntu Xenial)
 # remove the dependency from server and RocksDB so it can build properly
 if ! apt-cache madison libzstd-dev | grep 'libzstd-dev' >/dev/null 2>&1