Update upgrade-agent plugin to 1.1.290 (#2531)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 084fc8dc-c246-4427-ab40-d24e769453dd

.github/plugin/marketplace.json

@@ -1389,7 +1389,7 @@
     {
       "name": "upgrade-agent",
       "description": "AI-powered upgrade assistant for upgrading and migrating applications. Helps modernize legacy code and upgrade .NET applications to current frameworks.",
-      "version": "1.1.247",
+      "version": "1.1.290",
       "author": {
         "name": "Microsoft",
         "url": "https://www.microsoft.com"
@@ -1408,7 +1408,7 @@
         "source": "github",
         "repo": "microsoft/upgrade-agent-plugins",
         "path": "plugins/upgrade-agent",
-        "sha": "a70e1ae1ff63dd19ff874e874b4b587a5291f68a"
+        "sha": "559f6fea2deea78fb5adf2cfacba2a5151a5fa7f"
       }
     },
     {