Exclude gosec G118 rule from client-scan CI

G118 (context cancellation not called) was added in gosec v2.24.0
(Feb 27, 2026) and produces false positives for cancel functions
that are called in goroutines or stored for deferred invocation.
The CI uses gosec@master which pulled in this new rule automatically.

Author: lrsaturnino

.github/workflows/client.yml

@@ -245,7 +245,7 @@ jobs:
       - uses: securego/gosec@master
         with:
           args: |
-            -exclude=G115
+            -exclude=G115,G118
             -exclude-dir=pkg/chain/ethereum/beacon/gen
             -exclude-dir=pkg/chain/ethereum/ecdsa/gen
             -exclude-dir=pkg/chain/ethereum/threshold/gen