Merge pull request #1368 from puppetlabs/pdksync_remove_debian_9

pdksync - (CONT-130) - Dropping Support for Debian 9

Author: LukasAud

metadata.json

@@ -55,7 +55,6 @@
     {
       "operatingsystem": "Debian",
       "operatingsystemrelease": [
-        "9",
         "10",
         "11"
       ]