Added ability to pass in an optional PR number as a parameter

[credfeto]

So so it can be used in a workflow that creates a PR automatically like repo-sync/pull-request then add in labels at creation rather than having to run an additional workflow

name: Auto PR Creation
on:
  push:
    branches-ignore:
    - master
    - main

jobs:
  create-pull-request:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v3
      with:
        fetch-depth: 1
        token: ${{ secrets.GITHUB_TOKEN }}
    - run: |
        echo COMMIT_MSG=`git log -1 --pretty=%B` >> $GITHUB_ENV

    - id: open-pr
      uses: repo-sync/[email protected]
      with:
        source_branch: ""                     # If blank, default: triggered branch
        destination_branch: "main"            # If blank, default: master
        pr_assignee: "${{ github.actor }}"    # Comma-separated list (no spaces)
        pr_label: "auto-pr"                   # Comma-separated list (no spaces)
        pr_draft: true                        # Creates pull request as draft
        pr_title: "${{ env.COMMIT_MSG }}"
        pr_body: "${{ steps.pr-template.outputs.content }}"
        github_token: ${{ secrets.GITHUB_TOKEN }}

    - name: Details
      run: |
          echo "URL: ${{steps.open-pr.outputs.pr_url}}"
          echo "PR: ${{steps.open-pr.outputs.pr_number}}"
          echo "CF: ${{steps.open-pr.outputs.has_changed_files}}"

    - uses: credfeto/labeler@feature/pass-in-pull-request-or-issue
      with:
        repo-token: "${{ secrets.GITHUB_TOKEN }}"
        configuration-path: .github/labeler.yml
        sync-labels: true
        pr-number: ${{steps.open-pr.outputs.pr_number}}

Also would fix https://github.com/actions/labeler/issues/304