Reduce permissions to this org/repo

[BigLep]

In the rush to set this repo up and make bulk changes, extensive permissions were given. Actions that should be taken:

Reduce repo specific permissions

We currently have

  github-mgmt:
    collaborators:
      admin:
        - andyschwab-admin
        - arajasek
        - galargh
        - jennijuju
        - JesseXie
        - mastrwayne-admin
      push:
        - autonome
        - mroth
        - scotthconner
        - web3risk-admin

Lets remove all the direct collaborators.
We can move these folks to the github-mgmt team:

• andyschwab-admin
• arajasek
• jennijuju
• mastrwayne-admin
  since they are already owners per https://github.com/orgs/filecoin-project/people?query=role%3Aowner

I believe the rest can be dropped.

Remove org ownership

In this event @galargh and I were elevated to org owners. We should be removed. With github-mgmt setup and having access there, we should be self-sufficient in helping with future permission needs.

[BigLep]

@galargh or @andyschwab-admin : are you ok to take care of this cleanup?