move away from `benjohnson/clock`

[sukunrt]

It's archived. We can use
filecoin-project/clock

          Let's do this in a separate PR. 

Separately, should we ask them to move this to the libp2p org?

Originally posted by @sukunrt in #3231 (comment)

[guillaumemichel]

What would be the reason for moving the repo to the libp2p org?

[p-shahi]

Will use the filecoin-project version of this repo and revisit later in case we want to migrate it to the libp2p org

[guillaumemichel]

See #3293 (comment)

[sukunrt]

Let's keep this as it is for now. It has been working fine for us. Let's move it to the libp2p org when we need to make a change to the clock package.

[MarcoPolo]

Sounds good. The next Go version may also have synctest which will change how we fake time.