Deny stdout/stderr printing in uv crate via clippy (#16695)

Follow-up from https://github.com/astral-sh/uv/pull/16690, in `uv` every
command should be using `write!(...)/writeln!(...)` with the `Printer`
abstraction instead of bypassing control with the standard printing
functions. This lint ensures that.

crates/uv/src/lib.rs

@@ -1,3 +1,5 @@
+#![deny(clippy::print_stdout, clippy::print_stderr)]
+
 use std::borrow::Cow;
 use std::ffi::OsString;
 use std::fmt::Write;