Transaction pool metrics are broken

[Longarithm]

During #10543 tx pool size and count metrics were showing continuous growth: https://nearinc.grafana.net/goto/6axQo--IR?orgId=1
Something is broken with computation using "deltas" - updating metrics with txs inserted/deleted for chunks. With naive metrics computation, sizes were around zero, as expected. Code Longarithm/nearcore@master...more-metrics-4

[aborg-dev]

I think the root cause is that shard_id label is broken now for this metric, as instead of numeric values 0..5 we now have string values "s0.v3", "s1.v3", ... (see more info here https://near.zulipchat.com/#narrow/stream/308695-nearone.2Fprivate/topic/.5Bnode.5D.20Oncall.2030.20Mar.20-.205.20Apr.202024/near/431322538).

Can you try specifying a concrete label and see if this fixes the problem? Also, does the linked graph collect data from RPC nodes? For them the TX pool is sometimes growing without cleanup in some corner-cases (when they have validator keys but are not actively validating blocks).