Update releases.json to reflect correct support phase for .NET 6.0 (#9413)

* Update releases.json

* Update releases-index.json

release-notes/6.0/releases.json

@@ -4,7 +4,7 @@
   "latest-release-date": "2024-07-09",
   "latest-runtime": "6.0.32",
   "latest-sdk": "6.0.424",
-  "support-phase": "active",
+  "support-phase": "maintenance",
   "release-type": "lts",
   "eol-date": "2024-11-12",
   "lifecycle-policy": "https://dotnet.microsoft.com/platform/support/policy/",
@@ -24677,4 +24677,4 @@
       }
     }
   ]
-}
+}

release-notes/releases-index.json

@@ -51,7 +51,7 @@
             "latest-runtime": "6.0.32",
             "latest-sdk": "6.0.424",
             "product": ".NET",
-            "support-phase": "active",
+            "support-phase": "maintenance",
             "eol-date": "2024-11-12",
             "release-type": "lts",
             "releases.json": "https://dotnetcli.blob.core.windows.net/dotnet/release-metadata/6.0/releases.json",