style: fix new lints

The Rust compiler seems to have gotten smarter at finding unused or
redundant imports.

crates/cli/src/wtr.rs

@@ -1,6 +1,6 @@
 use std::io::{self, IsTerminal};
 
-use termcolor::{self, HyperlinkSpec};
+use termcolor::HyperlinkSpec;
 
 /// A writer that supports coloring with either line or block buffering.
 #[derive(Debug)]