Broken link: Add SSRN URL to excluded links list (#56050)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: am-stead <102995847+am-stead@users.noreply.github.com>

Author: Copilot

src/links/lib/excluded-links.yml

@@ -99,3 +99,4 @@
 - is: https://www.tpgi.com/color-contrast-checker/
 - startsWith: https://github.com/githubcustomers/enterprise-preview-program
 - is: https://aka.ms/copiloteclipse
+- is: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1375604