chore: add FIL-B to codeowners in synapse-sdk

[rjan90]

Summary

Add/consolidate fil-b members into FIL-B team, resolves CI failure here: FilOzone/synapse-sdk#507 (comment)

[github-actions]

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

Terraform plans

FilOzone

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

Terraform will perform the following actions:

  # github_repository_collaborator.this["synapse-sdk:longfeiwan9"] will be destroyed
  # (because key ["synapse-sdk:longfeiwan9"] is not in for_each map)
  - resource "github_repository_collaborator" "this" {
      - id                          = "synapse-sdk:longfeiWan9" -> null
      - invitation_id               = "297745072" -> null
      - permission                  = "push" -> null
      - permission_diff_suppression = false -> null
      - repository                  = "synapse-sdk" -> null
      - username                    = "longfeiWan9" -> null
    }

  # github_repository_collaborator.this["synapse-sdk:nijoe1"] will be destroyed
  # (because key ["synapse-sdk:nijoe1"] is not in for_each map)
  - resource "github_repository_collaborator" "this" {
      - id                          = "synapse-sdk:nijoe1" -> null
      - invitation_id               = "297745067" -> null
      - permission                  = "push" -> null
      - permission_diff_suppression = false -> null
      - repository                  = "synapse-sdk" -> null
      - username                    = "nijoe1" -> null
    }

  # github_repository_collaborator.this["synapse-sdk:snissn"] will be destroyed
  # (because key ["synapse-sdk:snissn"] is not in for_each map)
  - resource "github_repository_collaborator" "this" {
      - id                          = "synapse-sdk:snissn" -> null
      - permission                  = "push" -> null
      - permission_diff_suppression = false -> null
      - repository                  = "synapse-sdk" -> null
      - username                    = "snissn" -> null
    }

  # github_team_repository.this["fil-b:synapse-sdk"] will be created
  + resource "github_team_repository" "this" {
      + etag       = (known after apply)
      + id         = (known after apply)
      + permission = "push"
      + repository = "synapse-sdk"
      + team_id    = "15475023"
    }

Plan: 1 to add, 0 to change, 3 to destroy.

[github-actions]

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

Access Changes

User trruckerfling:
  - will gain push permission to synapse-sdk

[rjan90]

Merging without approval, since almost all of the FIL-B team already had push access