socket.once is undefined error during agent shutdown on mobile

[bryce-mcmath]

This error causes agent.shutdown() to fail before it sets agent.isInitialized to false which prevents the graceful shutdown and restart of mobile Credo agents (between auth lockouts for example)

Here is the relevant line (I think):

credo-ts/packages/core/src/transport/WsOutboundTransport.ts

Lines 44 to 45 in e57bf8f

	stillOpenSocketClosingPromises.push(new Promise((resolve) => socket.once('close', resolve)))
	socket.close()

There has been some suggestions in Credo Discord on how to fix, I would make a PR myself but I'm going on vacation for a few weeks

[bryce-mcmath]

@jleach @cvarjao @al-rosenthal FYI