Merge pull request #8362 from Gacko/mtssr

Ingress NGINX: Promote Test Runner v1.3.1.

Author: k8s-ci-robot

registry.k8s.io/images/k8s-staging-ingress-nginx/images.yaml

@@ -273,6 +273,7 @@
     "sha256:9d6e57395138b00b865035f267effabd5faf40eabe12601f3dc6c29f9d8fdecf": ["v1.2.4"]
     "sha256:9011136d1081fd65b76baa345dd8ad8ee30b037d33cde43a89959f5f7e6e5223": ["v1.2.5"]
     "sha256:ab913836443d9c67f817b348ec334e98730ed55931a524fae9f09359f3fe7cd8": ["v1.3.0"]
+    "sha256:5df4d33e7a660afc361aef07af70908a2f9ed4f3251ee0ff6df25d179a03f311": ["v1.3.1"]
     "sha256:3e7bda4cf5111d283ed1e4ff5cc9a2b5cdc5ebe62d50ba67473d3e25b1389133": ["v2.0.0"]
     "sha256:0301aff18d076a3726a0c7c07c68db3218dc90d56a3ed419868e21c12114549e": ["v2.0.1"]
     "sha256:d150d220752ed7479a1a1400be69bcca7bf5bf4b49d0d48890927f086eef5e2d": ["v2.0.2"]