Drop hostname formatter completely -- the default jobmetricformatter …

…is fine here and does the same thing

lib/galaxy/job_metrics/instrumenters/hostname.py

@@ -4,21 +4,14 @@
 from typing import Any
 
 from . import InstrumentPlugin
-from .. import formatting
 
 log = logging.getLogger(__name__)
 
 
-class HostnameFormatter(formatting.JobMetricFormatter):
-    def format(self, key: str, value: Any):
-        return formatting.FormattedMetric(key, value)
-
-
 class HostnamePlugin(InstrumentPlugin):
     """Gather hostname"""
 
     plugin_type = "hostname"
-    formatter = HostnameFormatter()
 
     def __init__(self, **kwargs):
         pass