ci: increase timeout of Multus-CNI conformance e2e (#5429)

Signed-off-by: zhangzujian <[email protected]>

Author: zhangzujian

.github/workflows/build-x86-image.yaml

@@ -1384,7 +1384,7 @@ jobs:
       - build-kube-ovn
       - build-e2e-binaries
     runs-on: ubuntu-24.04
-    timeout-minutes: 10
+    timeout-minutes: 15
     strategy:
       fail-fast: false
       matrix: