fix(ci): stabilize full release validation

.github/workflows/full-release-validation.yml

@@ -246,6 +246,23 @@ jobs:
             echo "- Target SHA: \`${TARGET_SHA}\`"
           } >> "$GITHUB_STEP_SUMMARY"
 
+          cancel_same_sha_push_ci() {
+            local run_ids run_id
+            run_ids="$(
+              gh run list --workflow ci.yml --limit 100 --json databaseId,event,headSha,status \
+                --jq 'map(select(.event == "push" and .headSha == env.TARGET_SHA and (.status == "queued" or .status == "in_progress" or .status == "waiting" or .status == "pending"))) | .[].databaseId'
+            )"
+            if [[ -z "${run_ids// }" ]]; then
+              return 0
+            fi
+            while IFS= read -r run_id; do
+              [[ -n "${run_id// }" ]] || continue
+              echo "Cancelling same-SHA push CI run ${run_id}; Full Release Validation dispatches the full manual CI child for ${TARGET_SHA}."
+              gh run cancel "$run_id" || gh api -X POST "repos/${GITHUB_REPOSITORY}/actions/runs/${run_id}/force-cancel" || true
+            done <<< "$run_ids"
+          }
+
+          cancel_same_sha_push_ci
           dispatch_and_wait ci.yml -f target_ref="$TARGET_SHA"
 
   release_checks: