fix: fix the reference to unlink from link

wfassoc-exec/src/runner.rs

@@ -125,7 +125,7 @@ fn run_ext_unlink(
 ) -> Result<()> {
     let exts = stringified_exts_to_indices(&program, exts)?;
     for index in exts {
-        program.link_ext(scope, index)?;
+        program.unlink_ext(scope, index)?;
     }
 
     println!("File extension now is unlinked.");