Instead of creating multiple workflows, you could create one workflow with multiple jobs that need each other via the needs: keyword. https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#jobsjob_idneeds

on:
  pull_request:

jobs:
  tf-plan-upload:
    runs-on: ubuntu-latest
    steps:
      - run: echo "This job does TF plan and uploads"

  tf-plan-download-opa-scan:
    needs: [tf-plan-upload]
    runs-on: ubuntu-latest
    steps:
      - run: echo "This job downloads the TF plan and runs the OPA scan"