Removes Istio flavor for 1.12.1

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

Author: danehans

site/manifest.json

@@ -39,21 +39,6 @@
       ],
       "is_security_patch": false
     },
-    {
-      "version": "1.12.1",
-      "flavor": "istio",
-      "flavor_version": 1,
-      "k8s_versions": [
-        "1.19",
-        "1.20",
-        "1.21",
-        "1.22"
-      ],
-      "release_notes": [
-        "https://istio.io/latest/news/releases/1.12.x/announcing-1.12.1/"
-      ],
-      "is_security_patch": false
-    },
    {
       "version": "1.11.3",
       "flavor": "tetrate",