chore(ci): switch auto-merge from seahaven-bot to Mergify (#34)

.github/workflows/auto-merge.yaml

@@ -1,44 +0,0 @@
-name: Enable auto-merge
-
-on:
-  pull_request:
-    types: [opened, ready_for_review, reopened, synchronize]
-    branches: [main]
-
-concurrency:
-  group: enable-auto-merge-${{ github.event.pull_request.number }}
-  cancel-in-progress: true
-
-permissions:
-  contents: write
-  pull-requests: write
-
-jobs:
-  enable:
-    if: >-
-      github.event.pull_request.draft == false
-      && github.event.pull_request.head.repo.full_name == github.repository
-      && github.event.pull_request.user.login != 'dependabot[bot]'
-      && github.event.pull_request.user.login != 'renovate[bot]'
-    runs-on: ubuntu-latest
-    steps:
-      - name: Enable squash auto-merge
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          PR: ${{ github.event.pull_request.number }}
-          REPO: ${{ github.repository }}
-        run: |
-          set -euo pipefail
-          if [ "$(gh pr view "$PR" --repo "$REPO" --json autoMergeRequest --jq '.autoMergeRequest != null')" = "true" ]; then
-            echo "auto-merge already enabled"
-            exit 0
-          fi
-          if ! out=$(gh pr merge "$PR" --repo "$REPO" --auto 2>&1); then
-            echo "$out"
-            if [ "$(gh pr view "$PR" --repo "$REPO" --json autoMergeRequest --jq '.autoMergeRequest != null')" = "true" ]; then
-              echo "auto-merge already enabled"
-              exit 0
-            fi
-            exit 1
-          fi
-          printf '%s\n' "$out"

.mergify.yml

@@ -0,0 +1 @@
+extends: .github