20 timer callback slots may not be enough for C6

[bugadani]

I'm getting this error:

[WARN] - Failed to set timer function 40824b98

The set of features I have enabled on esp-wifi are as follows, so I don't have BLE and coex enabled (meaning the library should be limited to 20 timers)

features = [
    "phy-enable-usb",
    "ps-max-modem",
    "wifi",
    "async",
    "embassy-net",
    "tcp",
    "dns",
    "ipv4",
    "dhcpv4"
]

[bjoernQ]

Given the size of a timer isn't that huge I guess we can just unconditionally bump it a bit 🤔

[bugadani]

I think we are at the point where we could instead start to heap-allocate these things.

[bjoernQ]

Also an option

[MabezDev]

These queues are now heap allocated.