[llvm] [CI] Add queue size, running count metrics (PR #122714)

[Nathan Gauër via llvm-commits]

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@@ -26,7 +26,67 @@ class JobMetrics:
     workflow_id: int
 
 
-def get_metrics(github_repo: github.Repository, workflows_to_track: dict[str, int]):
+ at dataclass
+class GaugeMetric:
+    name: str
+    value: int
+    time_ns: int
+
+
+def get_sampled_workflow_metrics(github_repo: github.Repository):
+    """Gets global statistics about the Github workflow queue
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Keenuts wrote:

I don't think so, since I'm filtering the lists depending on `WORKFLOWS_TO_TRACK`

https://github.com/llvm/llvm-project/pull/122714