[meta] update security policy to use GitHub PVR instead of Tidelift

Author: ljharb

SECURITY.md

@@ -6,6 +6,4 @@ Latest major/minor version is supported only for security updates.
 
 ## Reporting a Vulnerability
 
-To report a security vulnerability, please use the
-[Tidelift security contact](https://tidelift.com/security).
-Tidelift will coordinate the fix and disclosure.
+To report a security vulnerability, please [file a private vulnerability report via GitHub](https://github.com/import-js/eslint-plugin-import/security/advisories/new).