Bitswap client CPU hotspots

# Goals

Under heavy load, we're seeing high CPU usage in Lassie originating in Bitswap. Looks like a couple functions are pretty heavy CPU consumers:
- `SessionInterestManager.RemoveSession`
- `MessageQueue.ExtractOutgoingMessage` (and `Wantlist.Entries` within it)
This pushes us towards 700%+ CPU usage on a Saturn node that affects overall performance.

Pprof visualization:
Source data:
[cpu.pprof.zip](https://github.com/ipfs/boxo/files/11444857/cpu.pprof.zip)
Lassie binaries (this is from the x86_64 build we think):
https://github.com/filecoin-project/lassie/releases/tag/v0.9.2

I suspect these hotspots are pretty common to heavy bitswap client usage and are worth optimizing.