Discontinue `package:timing`

[davidmorgan]

There was an old build_runner issue suggesting to copy timing into build_runner since it's not really used for anything else.

That seems like a good idea to me as it will make it easier to roll into google3.

So: dart-lang/build#4192

--> package:timing can be discontinued, I think.

[devoncarew]

It looks like 7 packages depend on it, none of them high volume: https://pub.dev/packages?q=dependency%3Atiming. 7 is a small number.

It looks like this was migrated out of build in 2018; cc @jakemac53, @natebosch

I think discontinuing is reasonable. The process would be:

• updating the readme (it's discontinued, w/ some recourse options)
• publish one last time
• mark the pub package as discontinued
• delete pkgs/timing

We'd want to keep this issue open (for feedback) for a bit before taking those steps.

[jakemac53]

I can't remember the last time it actually needed an update either, so fwiw I think its low effort to maintain and we would likely spend more effort deprecating it than maintaining it for X years 🤷 .

[natebosch]

discontinuing SGTM