Update dependency puppet/extlib to v8

Author: renovate[bot]

Puppetfile

@@ -47,7 +47,7 @@ mod 'puppet/augeasproviders_shellvar', '6.0.1'
 mod 'puppet/chrony', '5.0.0'
 mod 'puppet/cron', '5.0.0'
 mod 'puppet/epel', '6.0.0'
-mod 'puppet/extlib', '7.5.1'
+mod 'puppet/extlib', '8.0.0'
 mod 'puppet/hosts', '0.1.0'
 mod 'puppet/ipset', '5.0.0'
 mod 'puppet/kmod', '5.0.0'