GHA: Simplify step to check author's membership (duckduckgo#3609)

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Task/Issue URL:
https://app.asana.com/0/1174433894299346/1205611423977807/f

### Description
- We don’t need to use Github API to check the membership of the author
of a PR
- Any PR created by a fork should go through the External PR step.

.github/workflows/action-pr-opened.yaml

@@ -8,18 +8,12 @@ jobs:
  validate-pr:
  name: Validate Pull Request
  runs-on: ubuntu-latest
- outputs:
- output1: ${{ steps.step1.outputs.external }}
  steps:
  - name: Checking Pull Request sender membership
- id: step1
- uses: malmstein/github-asana-action@master
- with:
- github-pat: ${{ secrets.GT_DAXMOBILE }}
- action: 'check-pr-membership'
+ run: echo "Checking author membership in the organization"
  process-internal-pr:
  name: Process internal Pull Request
- if: ${{ needs.validate-pr.outputs.output1 == 'false' }}
+ if: ${{ github.event.pull_request.user.login == github.event.pull_request.base.repo.owner.login}}
  runs-on: ubuntu-latest
  needs: validate-pr
  permissions:
@@ -34,7 +28,7 @@ jobs:
  is-pinned: true
  process-external-pr:
  name: Process external Pull Request
- if: ${{ needs.validate-pr.outputs.output1 == 'true' }}
+ if: ${{ github.event.pull_request.user.login != github.event.pull_request.base.repo.owner.login}}
  runs-on: ubuntu-latest
  needs: validate-pr
  permissions: