add rvagg to fips-editors

[rvagg]

Updating to match https://github.com/filecoin-project/FIPs/blob/master/CODEOWNERS so I can merge.

@raulk is missing from this list, would you like me to put you on here too Raul to get these in sync?

[github-actions]

The following access changes will be introduced as a result of applying the plan:

Access Changes

User rvagg:
  - will have the permission to fips change from push to admin

[github-actions]

Before merge, verify that all the following plans are correct. They will be applied as-is after the merge.

Terraform plans

filecoin-project

Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # github_team_membership.this["fips-editors:rvagg"] will be created
  + resource "github_team_membership" "this" {
      + etag     = (known after apply)
      + id       = (known after apply)
      + role     = "member"
      + team_id  = "5698214"
      + username = "rvagg"
    }

Plan: 1 to add, 0 to change, 0 to destroy.