Revisit Mergify settings

 * Add v4.0.x
 * Drop more complex workflows/backport rules we
   do not really use in practice

Author: michaelklishin

.github/mergify.yml

@@ -13,139 +13,36 @@ pull_request_rules:
       label:
         add:
           - make
-  - name: Automatically backport to v3.13.x based on label
+  - name: Automatically backport to v4.0.x based on label
     conditions:
       - base=main
-      - label=backport-v3.13.x
+      - label=backport-v4.0.x
+      - label!=backport-v3.13.x
       - label!=backport-v3.12.x
-      - label!=backport-v3.11.x
-      - label!=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.13.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.13.x & v3.12.x based on label
-    conditions:
-      - base=main
-      - label=backport-v3.13.x
-      - label=backport-v3.12.x
-      - label!=backport-v3.11.x
-      - label!=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.13.x
-        labels:
-          - backport-v3.12.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.13.x, v3.12.x & v3.11.x based on labels
-    conditions:
-      - base=main
-      - label=backport-v3.13.x
-      - label=backport-v3.12.x
-      - label=backport-v3.11.x
-      - label!=backport-v3.10.x
     actions:
       backport:
         branches:
-          - v3.13.x
-        labels:
-          - backport-v3.12.x
-          - backport-v3.11.x
+          - v4.0.x
         assignees:
           - "{{ author }}"
-  - name: Automatically backport to v3.13.x, v3.12.x, v3.11.x & v3.10.x based on labels
+  - name: Automatically backport to v3.13.x based on label
     conditions:
-      - base=main
+      - base=v4.0.x
       - label=backport-v3.13.x
-      - label=backport-v3.12.x
-      - label=backport-v3.11.x
-      - label=backport-v3.10.x
+      - label!=backport-v3.12.x
     actions:
       backport:
         branches:
           - v3.13.x
-        labels:
-          - backport-v3.12.x
-          - backport-v3.11.x
-          - backport-v3.10.x
         assignees:
           - "{{ author }}"
   - name: Automatically backport to v3.12.x based on label
     conditions:
       - base=v3.13.x
       - label=backport-v3.12.x
-      - label!=backport-v3.11.x
-      - label!=backport-v3.10.x
     actions:
       backport:
         branches:
           - v3.12.x
         assignees:
           - "{{ author }}"
-  - name: Automatically backport to v3.12.x & v3.11.x based on labels
-    conditions:
-      - base=v3.13.x
-      - label=backport-v3.12.x
-      - label=backport-v3.11.x
-      - label!=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.12.x
-        labels:
-          - backport-v3.11.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.12.x, v3.11.x & v3.10.x based on labels
-    conditions:
-      - base=v3.13.x
-      - label=backport-v3.12.x
-      - label=backport-v3.11.x
-      - label=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.12.x
-        labels:
-          - backport-v3.11.x
-          - backport-v3.10.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.11.x based on label
-    conditions:
-      - base=v3.12.x
-      - label=backport-v3.11.x
-      - label!=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.11.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.11.x & v3.10.x based on labels
-    conditions:
-      - base=v3.12.x
-      - label=backport-v3.11.x
-      - label=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.11.x
-        labels:
-          - backport-v3.10.x
-        assignees:
-          - "{{ author }}"
-  - name: Automatically backport to v3.10.x based on label
-    conditions:
-      - base=v3.11.x
-      - label=backport-v3.10.x
-    actions:
-      backport:
-        branches:
-          - v3.10.x
-        assignees:
-          - "{{ author }}"