fix(prometheus): pass gauge labels positionally after upstream merge

Merging litellm_internal_staging put the codebase over two ceilings that
this branch is responsible for one violation of each.

The _LabeledGauge protocol declared labels(**labels), which LIT008 bans
outright, and the keyword call also cost a reportGeneralTypeIssues. Both
go away by passing label values positionally, which prometheus_client
accepts and which the protocol's remove() already did, so the two calls
are now consistent and the ordered values are computed once.

Also assert observable output in the no-op metric test instead of relying
on it not raising.

litellm/integrations/prometheus.py

@@ -160,7 +160,7 @@ def _get_budget_metrics_per_request_timeout() -> float:
 class _LabeledGauge(Protocol):
     """Structural type shared by ``prometheus_client.Gauge`` and the no-op / label-excluding wrappers above."""
 
-    def labels(self, **labels: str) -> _LabeledGauge: ...
+    def labels(self, *labelvalues: str) -> _LabeledGauge: ...
 
     def set(self, value: float) -> None: ...
 
@@ -2171,13 +2171,14 @@ class PrometheusLogger(CustomLogger):
             enum_values=enum_values,
             label_context=label_context,
         )
+        label_values: Final = tuple(labels.get(name, "") for name in labelnames)
         if value is not None:
             self._drop_superseded_team_series(gauge=gauge, labelnames=labelnames, labels=labels)
-            gauge.labels(**labels).set(value)
+            gauge.labels(*label_values).set(value)
             return
 
         try:
-            gauge.remove(*(labels.get(name, "") for name in labelnames))
+            gauge.remove(*label_values)
         except KeyError:
             # No child series for this labelset, which is the common case:
             # the team never had a limit for this model.

tests/test_litellm/integrations/test_prometheus_team_rate_limit_metrics.py

@@ -128,10 +128,9 @@ def test_labels_carry_team_and_requested_model():
     _set_team_metrics(logger, _payload_with_headers(dict(ALL_TEAM_HEADERS)))
 
     for metric_name in TEAM_RATE_LIMIT_METRICS:
-        labels_kwargs = getattr(logger, metric_name).labels.call_args.kwargs
-        assert labels_kwargs["team"] == "team-abc"
-        assert labels_kwargs["team_alias"] == "research"
-        assert labels_kwargs["model"] == "gpt-4o-mini"
+        labelnames = PrometheusMetricLabels.get_labels(metric_name)
+        label_values = getattr(logger, metric_name).labels.call_args.args
+        assert dict(zip(labelnames, label_values, strict=True)) == TEAM_LABELS
 
 
 def test_emits_nothing_when_team_has_no_configured_limits():
@@ -353,10 +352,14 @@ def test_excluded_label_wrapper_cannot_remove_when_every_label_is_excluded():
 
 
 def test_noop_metric_remove_is_inert():
+    """A disabled metric answers every call without recording or raising."""
     metric = NoOpMetric()
 
-    metric.labels(**TEAM_LABELS).set(60)
-    metric.remove(*TEAM_LABELS.values())
+    child = metric.labels(*TEAM_LABELS.values())
+
+    assert child is metric
+    assert child.set(60) is None
+    assert metric.remove(*TEAM_LABELS.values()) is None
 
 
 def test_retires_the_old_series_when_a_team_is_renamed():