Update .NET SDK to 8.0.419 to pick up latest security patches

Update from .NET SDK 8.0.303 to 8.0.419 (March 10, 2026) to pick up
the latest security and reliability patches for .NET 8.0.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: TravisEz13

global.json

@@ -1,6 +1,6 @@
 {
     "sdk": {
-        "version": "8.0.303",
+        "version": "8.0.419",
         "rollForward": "latestMajor"
     }
 }