[CI] Make Metrics Container Use Python Logging

This patch makes the metrics container use the python logging library. This
is more of what we want given we're essentially just logging the status of
things. It also means we do not have to explicitly specify an output file
and lets us control verbosity a bit more cleanly.

.ci/metrics/metrics.py

diff --git a/.ci/metrics/metrics.py b/.ci/metrics/metrics.py
index 354b505..0dc61db 100644
--- a/.ci/metrics/metrics.py
+++ b/.ci/metrics/metrics.py
@@ -3,6 +3,7 @@
 import os
 from dataclasses import dataclass
 import sys
+import logging
 
 import github
 from github import Github
@@ -220,7 +221,7 @@
     """
 
     if len(workflow_metrics) == 0:
-        print("No metrics found to upload.", file=sys.stderr)
+        logging.info("No metrics found to upload.")
         return
 
     metrics_batch = []
@@ -249,9 +250,7 @@
     )
 
     if response.status_code < 200 or response.status_code >= 300:
-        print(
-            f"Failed to submit data to Grafana: {response.status_code}", file=sys.stderr
-        )
+        logging.info(f"Failed to submit data to Grafana: {response.status_code}")
 
 
 def main():
@@ -275,7 +274,7 @@
         current_metrics += get_sampled_workflow_metrics(github_repo)
 
         upload_metrics(current_metrics, grafana_metrics_userid, grafana_api_key)
-        print(f"Uploaded {len(current_metrics)} metrics", file=sys.stderr)
+        logging.info(f"Uploaded {len(current_metrics)} metrics")
 
         for workflow_metric in reversed(current_metrics):
             if isinstance(workflow_metric, JobMetrics):
@@ -287,4 +286,5 @@
 
 
 if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
     main()