Disable github actions

[asvetlov]

Now any PR fails on manylinux1 github action check.
It is very annoying.
@webknjaz can we temporarily disable the feature until it will work?

[aio-libs-bot]

GitMate.io thinks possibly related issues are #2067 (Disable Cookie Handling), #212 (github hook for readthedocs is disabled?), #2262 (Disable DNS cache), #1958 (Possibility to disable Server header), and #2477 (Github labels).

[webknjaz]

I made container run but it fails for some reason: https://github.com/aio-libs/aiohttp/runs/52842050

So I've temporarily added a filter to prevent this action from running on branches except for my experiments, now it looks like https://github.com/aio-libs/aiohttp/runs/52845231 and produces canceled neutral status. It's not red anymore.

Closing #3566 therefore.

[asvetlov]

Thanks, @webknjaz
Feel free to experiment but please don't break our main workflow until your work is not done.

[webknjaz]

That manylinux action should only be triggered for branches containing webknjaz substring so it should be good enough for experimenting and after it's green I'll merge that back to master