I/O polling

[armanbilge]

This PR is published as FS2 v3.12.0-RC1.

Upgrades to Cats Effect 3.6-e9aeb8c v3.6.0-RC1 which includes the new I/O polling system.

• Polling system cats-effect#3332

The following APIs can be implemented with I/O polling. I've done some in this PR, the rest might end up in follow-up PRs.

JVM Selector-based I/O

• SocketGroup and Socket
• DatagramSocketGroup and DatagramSocket
• UnixSockets

Native file descriptor polling-based I/O

• SocketGroup and Socket
• DatagramSocketGroup and DatagramSocket
• UnixSockets
• Processes and Process
• fs2.io.{stdin,stdout,stderr}

[yilinwei]

Just writing this down here before I forget,

I saw this error (which looks eerily like we're using an at before checking), I'm not certain why it's Unknown Source unfortunately.

java.lang.ArrayIndexOutOfBoundsException: 0
	at java.lang.StackTrace$.currentStackTrace$$anonfun$1(Unknown Source)
	at java.lang.StackTrace$$$Lambda$2.applyVoid(Unknown Source)
	at apply @ fs2.io.net.FdPollingSocket.go$1$$anonfun$2(Unknown Source)
	at apply @ fs2.io.net.FdPollingSocket.go$1(Unknown Source)
	at flatMap @ fs2.io.net.FdPollingSocket.go$1(Unknown Source)
	at pollReadRec @ fs2.io.net.FdPollingSocket.read$$anonfun$1(Unknown Source)
	at pollReadRec @ fs2.io.net.FdPollingSocket.read$$anonfun$1(Unknown Source)```

[armanbilge]

I'm not certain why it's Unknown Source unfortunately.

All Scala Native stack traces are like this currently. They don't include any source/line information, but they will soon.

[armanbilge]

I saw this error (which looks eerily like we're using an at before checking)

Fixed in 500e545.

[armanbilge]

Published 3.10-4b5f50b to Maven central.

[armanbilge]

Published 3.10-365636d to Maven central.

[armanbilge]

This PR is now published as a release candidate.
https://github.com/typelevel/fs2/releases/tag/v3.12.0-RC1