with the release of rust 1.67, let's bump to 1.66.1 (#7866)

# Description

This PR bumps the required rust version to 1.66.1.

# User-Facing Changes


# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/src/strings/encode_decode/base64.rs

@@ -151,8 +151,7 @@ fn action(
                     let val = val.clone();
                     let val = val.replace("\r\n", "").replace('\n', "");
 
-                    //match Engine::decode_string(&val, base64_engine) {
-                    match base64_engine.decode(&val) {
+                    match base64_engine.decode(val) {
                         Ok(decoded_value) => {
                             if output_binary {
                                 Value::binary(decoded_value, command_span)