ci: Respect do not merge tag in mergify (#2465)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

.github/mergify.yml

@@ -5,22 +5,24 @@ queue_rules:
 pull_request_rules:
   - name: Automatic merge on approval
     conditions:
-      - and:
-        - "#review-threads-unresolved=0"
-        - "#approved-reviews-by>=2"
-        - "#changes-requested-reviews-by=0"
-        - or:
-          - and:
-            - "label!=SR-Risk"
-            - "label!=C-Protocol-Critical"
-          - and:
-            - "label=SR-Risk"
-            - "approved-reviews-by=maurelian"
-          - and:
-            - "label=C-Protocol-Critical"
-            - or:
-              - "approved-reviews-by=tynes"
-              - "approved-reviews-by=smartcontracts"
+      and: 
+        - "label!=do-not-merge"
+        - and:
+          - "#review-threads-unresolved=0"
+          - "#approved-reviews-by>=2"
+          - "#changes-requested-reviews-by=0"
+          - or:
+            - and:
+              - "label!=SR-Risk"
+              - "label!=C-Protocol-Critical"
+            - and:
+              - "label=SR-Risk"
+              - "approved-reviews-by=maurelian"
+            - and:
+              - "label=C-Protocol-Critical"
+              - or:
+                - "approved-reviews-by=tynes"
+                - "approved-reviews-by=smartcontracts"
     actions:
       queue:
         name: default