fix(socketio): emit with ack race cond

[Totodore]

Motivation

With env with high CPU preemption (like CIs) a race condition might occur when using emit_with_ack methods. The ack oneshot chan was inserted in the pending acks map only after the packet emission. With a potential interrupt and a fast enough system the ack response was received before the chan being inserted in the map.

Solution

Insert the oneshot ack response handler before emitting the packet.

[codspeed-hq]

Merging this PR will not alter performance

✅ 87 untouched benchmarks

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_{Comparing fix-race-cond (602400c) with main (9fd9181)}