sync workflow github fork from upstream

sync-upstream.yml

# yamllint disable rule:truthy
# yamllint disable rule:document-start
name: Sync Upstream

on:
  schedule:
    - cron: "0 5 * * 0"
  workflow_dispatch:

jobs:
  sync-main:
    runs-on: ubuntu-latest
    permissions:
      contents: write
    env:
      UPSTREAM_REPO: https://github.com/oribarilan/lensline.nvim
      TARGET_BRANCH: main
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Configure git
        run: |
          git config user.name "${GITHUB_ACTOR}"
          git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
      - name: Merge upstream main
        run: |
          git remote add upstream "${UPSTREAM_REPO}"
          git fetch upstream "${TARGET_BRANCH}"
          git checkout "${TARGET_BRANCH}"
          git merge --no-edit "upstream/${TARGET_BRANCH}"
      - name: Push changes
        run: git push origin "${TARGET_BRANCH}"