docs: broken link (#12524)

docs/argo-server-sso.md

@@ -83,7 +83,7 @@ metadata:
     # Must evaluate to a boolean.
     # If you want an account to be the default to use, this rule can be "true".
     # Details of the expression language are available in
-    # https://github.com/antonmedv/expr/blob/master/docs/Language-Definition.md.
+    # https://github.com/antonmedv/expr/blob/master/docs/language-definition.md.
     workflows.argoproj.io/rbac-rule: "'admin' in groups"
     # The precedence is used to determine which service account to use whe
     # Precedence is an integer. It may be negative. If omitted, it defaults to "0".