Print errors regardless of logging filters

Before:
```console
$ RUST_LOG=foobar xh ssh://example.org
[no output]
```
After:
```console
$ RUST_LOG=foobar xh ssh://example.org
xh: error: builder error for url (ssh://example.org)

Caused by:
    URL scheme is not allowed
```

Reusing the `log` formatter for this was cute but ultimately
confusing.

Author: blyxxyz

src/main.rs

@@ -73,14 +73,15 @@ fn main() {
     log::debug!("{args:#?}");
 
     let native_tls = args.native_tls;
+    let bin_name = args.bin_name.clone();
 
     match run(args) {
         Ok(exit_code) => {
             process::exit(exit_code);
         }
         Err(err) => {
             log::debug!("{err:#?}");
-            log::error!("{err:?}");
+            eprintln!("{bin_name}: error: {err:?}");
             let msg = err.root_cause().to_string();
             if native_tls && msg == "invalid minimum TLS version for backend" {
                 eprintln!();