refactor: directly call signal handler

Not super-imporant I don't think, but it feels better to use `call1` instead of
`run_bound` on some Python code.

python/src/lib.rs

@@ -128,15 +128,15 @@ impl From<pythonize::PythonizeError> for Error {
 fn main(py: Python<'_>) {
     use clap::Parser;
 
-    // https://github.com/PyO3/pyo3/issues/3218
-    py.run_bound(
-        "import signal
-signal.signal(signal.SIGINT, signal.SIG_DFL)",
-        None,
-        None,
-    )
-    .unwrap();
-
+    let signal = py.import_bound("signal").unwrap();
+    signal
+        .getattr("signal")
+        .unwrap()
+        .call1((
+            signal.getattr("SIGINT").unwrap(),
+            signal.getattr("SIG_DFL").unwrap(),
+        ))
+        .unwrap();
     let args: Vec<_> = std::env::args().skip(1).collect();
     ::cql2_cli::Cli::parse_from(args).run()
 }