Remove unused FlatShapes And/Or (#14476)

# Description
This removes the need for the `shape_and` and `shape_or` entries in the
themes. We did not color those underlying FlatShapes or operators
differently.

Closes #14372
# User-Facing Changes
Our theme handling currently doesn't reject invalid entries so should
not cause an error. The non-functional nature was already documented.

crates/nu-lsp/src/lib.rs

@@ -576,7 +576,6 @@ impl LanguageServer {
             }
             Id::Value(shape) => {
                 let hover = String::from(match shape {
-                    FlatShape::And => "and",
                     FlatShape::Binary => "binary",
                     FlatShape::Block => "block",
                     FlatShape::Bool => "bool",