Remove And and Or pipeline elements (#7229)

# Description

Since we're not implementing `&&` or `||`, let's remove their pipeline
elements.

# User-Facing Changes

Nothing user facing. These were not yet implemented.

# 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-parser/src/parse_keywords.rs

@@ -1422,9 +1422,7 @@ pub fn parse_module_block(
 
                         pipeline
                     }
-                    LiteElement::Or(_, command)
-                    | LiteElement::And(_, command)
-                    | LiteElement::Redirection(_, _, command) => garbage_pipeline(&command.parts),
+                    LiteElement::Redirection(_, _, command) => garbage_pipeline(&command.parts),
                 }
             } else {
                 error = Some(ParseError::Expected("not a pipeline".into(), span));