ci: go-version-file must point into the subdir checkout

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: TeoSlayer

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
 
       - uses: actions/setup-go@v6
         with:
-          go-version-file: go.mod
+          go-version-file: trustedagents/go.mod
           cache: true
           cache-dependency-path: trustedagents/go.sum