.github: remove old mergify config (#11258)

.github/mergify.yml

-queue_rules:
-  - name: urgent
-    queue_conditions:
-      - "label=C-urgent"
-  - name: default
-    queue_conditions:
-      - "label!=C-urgent"
-      - author!=dependabot[bot]
-  - name: lowpriority
-    queue_conditions:
-      - author=dependabot[bot]
-
-pull_request_rules:
-  - name: Automatic merge on approval
-    conditions:
-      - and:
-        - "#review-threads-unresolved=0"
-        - "#approved-reviews-by>=1"
-        - "#changes-requested-reviews-by=0"
-        - "label!=do-not-merge"
-        - "label!=multiple-reviewers"
-        - "label!=mergify-ignore"
-        - "label!=M-do-not-merge"
-        - "label!=M-multiple-reviewers"
-        - "label!=M-mergify-ignore"
-        - "base=develop"
-    actions:
-      queue:
-        name: default
-        method: merge
-        merge_bot_account: OptimismBot
-  - name: Add merge train label
-    conditions:
-      - "queue-position >= 0"
-    actions:
-      comment:
-          message: |
-            This PR has been added to the merge queue, and will be merged soon.
-      label:
-        add:
-          - S-on-merge-train
-  - name: Remove merge train label
-    conditions:
-      - "queue-position = -1"
-    actions:
-      label:
-        remove:
-          - S-on-merge-train
-  - name: Ask to resolve conflict
-    conditions:
-      - conflict
-    actions:
-      comment:
-        message: Hey @{{author}}! This PR has merge conflicts. Please fix them before continuing review.
-      label:
-        add:
-          - S-conflict
-  - name: Remove conflicts label when conflicts gone
-    conditions:
-      - -conflict
-    actions:
-      label:
-        remove:
-          - S-conflict
-  - name: Notify author when added to merge queue
-    conditions:
-      - "check-pending=Queue: Embarked in merge train"
-    actions:
-      comment:
-        message: |
-          This PR is next in line to be merged, and will be merged as soon as checks pass.
-  - name: Notify author on queue failure
-    conditions:
-      - 'check-failure=Queue: Embarked in merge train'
-    actions:
-      comment:
-        message: >
-          Hey @{{ author }}, this pull request failed to merge and has been
-          dequeued from the merge train.  If you believe your PR failed in
-          the merge train because of a flaky test, requeue it by commenting
-          with `@mergifyio requeue`.
-
-          More details can be found on the `Queue: Embarked in merge train`
-          check-run.
-  - name: Add A-cannon label
-    conditions:
-      - 'files~=^cannon/'
-    actions:
-      label:
-        add:
-          - A-cannon
-  - name: Add A-op-batcher label
-    conditions:
-      - 'files~=^op-batcher/'
-    actions:
-      label:
-        add:
-          - A-op-batcher
-  - name: Add A-op-bootnode label
-    conditions:
-      - 'files~=^op-bootnode/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-bootnode
-  - name: Add A-op-chain-ops label
-    conditions:
-      - 'files~=^op-chain-ops/'
-    actions:
-      label:
-        add:
-          - A-op-chain-ops
-  - name: Add A-op-challenger label
-    conditions:
-      - 'files~=^op-challenger/'
-    actions:
-      label:
-        add:
-          - A-op-challenger
-  - name: Add A-op-e2e label
-    conditions:
-      - 'files~=^op-e2e/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-e2e
-  - name: Add A-op-heartbeat label
-    conditions:
-      - 'files~=^op-heartbeat/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-heartbeat
-  - name: Add A-op-node label
-    conditions:
-      - 'files~=^op-node/'
-    actions:
-      label:
-        add:
-          - A-op-node
-  - name: Add A-op-preimage label
-    conditions:
-      - 'files~=^op-preimage/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-preimage
-  - name: Add A-op-program label
-    conditions:
-      - 'files~=^op-program/'
-    actions:
-      label:
-        add:
-          - A-op-program
-  - name: Add A-op-proposer label
-    conditions:
-      - 'files~=^op-proposer/'
-    actions:
-      label:
-        add:
-          - A-op-proposer
-  - name: Add A-op-service label
-    conditions:
-      - 'files~=^op-service/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-service
-  - name: Add A-op-wheel label
-    conditions:
-      - 'files~=^op-wheel/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-op-wheel
-  - name: Add A-ops-bedrock label
-    conditions:
-      - 'files~=^ops-bedrock/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-ops-bedrock
-  - name: Add A-ops label
-    conditions:
-      - 'files~=^ops/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-ops
-  - name: Add A-pkg-contracts-bedrock label
-    conditions:
-      - 'files~=^packages/contracts-bedrock/'
-    actions:
-      label:
-        add:
-          - A-pkg-contracts-bedrock
-  - name: Add A-pkg-sdk label and ecopod reviewers
-    conditions:
-      - 'files~=^packages/sdk/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - A-pkg-sdk
-      request_reviews:
-        users:
-          - roninjin10
-  - name: Add M-docs label
-    conditions:
-      - 'files~=^(docs|specs)\/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - M-docs
-  - name: Add M-deletion label when files are removed
-    conditions:
-      - 'removed-files~=^/'
-    actions:
-      label:
-        add:
-          - M-deletion
-  - name: Add M-ci label when ci files are modified
-    conditions:
-      - 'files~=^\.(github|circleci)\/'
-      - '#label<5'
-    actions:
-      label:
-        add:
-          - M-ci