stdbuf: update to clap 4

tests/by-util/test_stdbuf.rs

@@ -27,17 +27,10 @@ fn test_stdbuf_line_buffered_stdout() {
 fn test_stdbuf_no_buffer_option_fails() {
     let ts = TestScenario::new(util_name!());
 
-    ts.ucmd().args(&["head"]).fails().stderr_is(&format!(
-        "error: The following required arguments were not provided:\n    \
-         --input <MODE>\n    \
-         --output <MODE>\n    \
-         --error <MODE>\n\n\
-         USAGE:\n    \
-         {1} {0} OPTION... COMMAND\n\n\
-         For more information try --help",
-        ts.util_name,
-        ts.bin_path.to_string_lossy()
-    ));
+    ts.ucmd()
+        .args(&["head"])
+        .fails()
+        .stderr_contains("The following required arguments were not provided:");
 }
 
 #[cfg(not(target_os = "windows"))]