mergify: Add merge automation

.github/mergify.yml

@@ -1,5 +1,80 @@
 pull_request_rules:
 
+- name: auto-merge
+  description: automatic merge for main with >= 2 approved reviews, all requested reviews have given feedback, not held, and CI is successful
+  conditions:
+    - "#approved-reviews-by>=2"
+    - "#review-requested=0"
+    - "#changes-requested-reviews-by=0"
+    - or:
+      - base=main
+      - base~=release-.*
+    - label!=hold
+    - label!=do-not-merge
+    - label!=needs-rebase
+    - check-success=DCO
+
+    # If files are changed in .github/, the actionlint check must pass
+    - or:
+      - and:
+        # regex should match the one in .github/workflows/actionlint.yml
+        - files~=.github/workflows/.*\.ya?ml$
+        - check-success=actionlint
+      - -files~=.github/workflows/.*\.ya?ml$
+
+    # e2e workflow
+    - or:
+      - and:
+        - check-success=e2e
+        - or:
+          - files~='.*\.py$'
+          - files~=pyproject.toml$
+          - files~=requirements.*\.txt$
+          - files~=.github/workflows/e2e.yml$
+      - and:
+        - -files~='.*\.py$'
+        - -files~=pyproject.toml$
+        - -files~=requirements.*\.txt$
+        - -files~=.github/workflows/e2e.yml$
+
+    # lint and test must pass if files change that would trigger this job
+    - or:
+      - and:
+        - check-success=lint
+        - check-success=test-workflow-complete
+        - or:
+          # see .github/workflows/lint.yml and test.yml
+          - files~=.*\.py$
+          - files~=pyproject.toml$
+          - files~=requirements.*\.txt$
+          - files~=tox.ini$
+          - files~=scripts/[^/]+\.sh$
+          - files~=.github/.*$
+      - and:
+        - -files~=.*\.py$
+        - -files~=pyproject.toml$
+        - -files~=requirements.*\.txt$
+        - -files~=tox.ini$
+        - -files~=scripts/[^/]+\.sh$
+        - -files~=.github/.*$
+
+    - or:
+      - and:
+        - or:
+          - files~='.*\.md'
+          - files='.markdownlint-cli2.yaml'
+          - files='.github/workflows/docs.yml'
+        - check-success=markdown-lint
+      - and:
+        - -files~='.*\.md'
+        - -files='.markdownlint-cli2.yaml'
+        - -files='.github/workflows/docs.yml'
+
+  actions:
+    merge:
+      method: merge
+    delete_head_branch:
+
 - name: label-cicd
   description: Automatically apply CI/CD label
   conditions: