Update clap to 4.1.8

This requires bumping the MSRV to 1.64.

It also updates the `terminal_size` crate that is pulled in by `clap` to
reduce duplicate dependencies.

README.md

@@ -418,7 +418,7 @@ binaries are also available: look for archives with `musl` in the file name.
 
 ### From source
 
-If you want to build `bat` from source, you need Rust 1.62.0 or
+If you want to build `bat` from source, you need Rust 1.64.0 or
 higher. You can then use `cargo` to build everything:
 
 ```bash