Exclude jquery-validation library from docfx build and Policheck (#36677)

* Initial plan

* Add jquery-validation exclusion to docfx.json

Co-authored-by: wadepickett <10985336+wadepickett@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: wadepickett <10985336+wadepickett@users.noreply.github.com>

Author: Copilot

aspnetcore/docfx.json

@@ -3,7 +3,7 @@
     "content": [
       {
         "files": [ "**/*.md", "**/*.yml" ], 
-        "exclude": [ "**/includes/**", "***/license.md", "**/obj/**", "***/readme.md", "**/sample/**", "**/samples/**", "_site/**" ], 
+        "exclude": [ "**/includes/**", "***/license.md", "**/obj/**", "***/readme.md", "**/sample/**", "**/samples/**", "_site/**", "**/lib/jquery-validation/**" ], 
         "group": "group1", 
         "src": "."
       },