Cut a new release automatically each month (#4146)

- **PR Description**

I regularly struggle to stay on top of releases, and that's because I
like to spend some time polishing the release notes and I don't always
have time for that. But that shouldn't block releases, so now releases
will happen automatically on the first Saturday of each month.

In order to block an automatic release, we simply need to add a
blocks-release label on any open PR or issue.

- **Please check if the PR fulfills these requirements**

* [ ] Cheatsheets are up-to-date (run `go generate ./...`)
* [ ] Code has been formatted (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#code-formatting))
* [ ] Tests have been added/updated (see
[here](https://github.com/jesseduffield/lazygit/blob/master/pkg/integration/README.md)
for the integration test guide)
* [ ] Text is internationalised (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#internationalisation))
* [ ] If a new UserConfig entry was added, make sure it can be
hot-reloaded (see
[here](https://github.com/jesseduffield/lazygit/blob/master/docs/dev/Codebase_Guide.md#using-userconfig))
* [ ] Docs have been updated if necessary
* [ ] You've read through your own file changes for silly mistakes etc

<!--
Be sure to name your PR with an imperative e.g. 'Add worktrees view'
see https://github.com/jesseduffield/lazygit/releases/tag/v0.40.0 for
examples
-->

.github/workflows/release.yml

@@ -0,0 +1,72 @@
+name: Automated Release
+
+on:
+  schedule:
+    # Runs at 2:00 AM UTC on the first Saturday of every month
+    - cron: '0 2 * * 6'
+  workflow_dispatch: # Allow manual triggering of the workflow
+
+jobs:
+  check-and-release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Check for changes since last release
+        run: |
+          if [ -z "$(git diff --name-only ${{ env.latest_tag }})" ]; then
+            echo "No changes detected since last release"
+            exit 1
+          fi
+
+      - name: Check for Blocking Issues/PRs
+        id: check_blocks
+        run: |
+          gh auth setup-git
+          gh auth status
+
+          echo "Checking for blocking issues and PRs..."
+
+          # Check for blocking issues
+          blocking_issues=$(gh issue list -l blocks-release --json number,title --jq '.[] | "- \(.title) (#\(.number))"')
+
+          # Check for blocking PRs
+          blocking_prs=$(gh pr list -l blocks-release --json number,title --jq '.[] | "- \(.title) (#\(.number)) (PR)"')
+
+          # Combine the results
+          blocking_items="$blocking_issues"$'\n'"$blocking_prs"
+
+          # Remove empty lines
+          blocking_items=$(echo "$blocking_items" | grep . || true)
+
+          if [ -n "$blocking_items" ]; then
+            echo "Blocking issues/PRs detected:"
+            echo "$blocking_items"
+            exit 1
+          fi
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Calculate next version
+        run: |
+          latest_tag=$(git describe --tags $(git rev-list --tags --max-count=1) || echo "v0.0.0")
+          echo "Latest tag: $latest_tag"
+          IFS='.' read -r major minor patch <<< "$latest_tag"
+          new_minor=$((minor + 1))
+          new_tag="$major.$new_minor.0"
+          echo "New tag: $new_tag"
+          echo "new_tag=$new_tag" >> $GITHUB_ENV
+
+      # This will trigger a deploy via .github/workflows/cd.yml
+      - name: Push New Tag
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git tag ${{ env.new_tag }}
+          git push origin ${{ env.new_tag }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}