(maint) Remove support for Ubuntu 14.04

Support for this has been dropped from the supported modules for some time, this one seems to have been missed in this process.

Author: david22swan

metadata.json

@@ -35,7 +35,6 @@
     {
       "operatingsystem": "Ubuntu",
       "operatingsystemrelease": [
-        "14.04",
         "18.04",
         "20.04"
       ]