fix: keep channels open

[richard-ramos]

@igor-sirotin reported the following error:

panic: send on closed channel

goroutine 228896 [running]:
github.com/waku-org/go-waku/waku/v2/api/publish.(*MessageQueue).Push(...)
        /Users/igorsirotin/Repositories/Status/status-go/vendor/github.com/waku-org/go-waku/waku/v2/api/publish/message_queue.go:131
github.com/status-im/status-go/wakuv2.(*Waku).Send(0x14002e9cf00, {0x14000bb8400?, 0xa?}, 0x1400347a000?, 0x107a22d50)
        /Users/igorsirotin/Repositories/Status/status-go/wakuv2/message_publishing.go:56 +0x140
github.com/status-im/status-go/wakuv2.(*PublicWakuAPI).Post(0x14006e4a3f0, {0x14001258f00?, 0x84?}, {{0x14001259100, 0x40}, {0x0, 0x0, 0x0}, {0x14001258f00, 0x40}, ...})
        /Users/igorsirotin/Repositories/Status/status-go/wakuv2/api.go:259 +0x568

Since this is happening because the channel is closed when the context is done, and the publish function is still being executed, attempting to add a message to the queue. To avoid this error, i just remove the need to close this channel, since it will be garbage collected eventually, since it will determine the channel to be unreachable will have its resources reclaimed whether or not it is closed, and also made Push and Pop functions cancelable by passing a context

Required to fix status-im/status-go#5661

[igor-sirotin]

Thank you!