[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

jupyter_server/prometheus/metrics.py

@@ -6,10 +6,12 @@
 """
 
 from prometheus_client import Gauge, Histogram, Info
+
 from jupyter_server._version import version_info as server_version_info
 
 try:
     from notebook._version import version_info as notebook_version_info
+
     v6_notebook_present = notebook_version_info != server_version_info
 except ImportError:
     # notebook._version is not present, so notebook v6 can not be present