Fix broken link to Code of Conduct in CONTRIBUTING.md

See gh-34180

Author: v-perfilev

CONTRIBUTING.md

@@ -16,7 +16,7 @@ First off, thank you for taking the time to contribute! :+1: :tada:
 
 ### Code of Conduct
 
-This project is governed by the [Spring Code of Conduct](CODE_OF_CONDUCT.adoc).
+This project is governed by the [Spring Code of Conduct](https://github.com/spring-projects/spring-framework/?tab=coc-ov-file#contributor-code-of-conduct).
 By participating you are expected to uphold this code.
 Please report unacceptable behavior to [email protected].