Remove unsued types (#14916)

# Description

`Type::Block` and `Type::Signature` do not correspond to any `Value`
cases and should be able to be removed.

crates/nu-parser/src/parse_keywords.rs

@@ -2259,7 +2259,7 @@ pub fn parse_module(
     module_comments.extend(inner_comments);
     let module_id = working_set.add_module(&module_name, module, module_comments);
 
-    let block_expr = Expression::new(working_set, Expr::Block(block_id), block_span, Type::Block);
+    let block_expr = Expression::new(working_set, Expr::Block(block_id), block_span, Type::Any);
 
     let module_decl_id = working_set
         .find_decl(b"module")

crates/nu-parser/src/parser.rs

@@ -3498,7 +3498,7 @@ pub fn parse_signature(working_set: &mut StateWorkingSet, span: Span) -> Express
 
     let sig = parse_signature_helper(working_set, Span::new(start, end));
 
-    Expression::new(working_set, Expr::Signature(sig), span, Type::Signature)
+    Expression::new(working_set, Expr::Signature(sig), span, Type::Any)
 }
 
 pub fn parse_signature_helper(working_set: &mut StateWorkingSet, span: Span) -> Box<Signature> {
@@ -4471,7 +4471,7 @@ pub fn parse_block_expression(working_set: &mut StateWorkingSet, span: Span) ->
 
     let block_id = working_set.add_block(Arc::new(output));
 
-    Expression::new(working_set, Expr::Block(block_id), span, Type::Block)
+    Expression::new(working_set, Expr::Block(block_id), span, Type::Any)
 }
 
 pub fn parse_match_block_expression(working_set: &mut StateWorkingSet, span: Span) -> Expression {

crates/nu-parser/src/type_check.rs

@@ -55,7 +55,6 @@ pub fn type_compatible(lhs: &Type, rhs: &Type) -> bool {
         (Type::Int, Type::Number) => true,
         (Type::Number, Type::Float) => true,
         (Type::Float, Type::Number) => true,
-        (Type::Closure, Type::Block) => true,
         (Type::Any, _) => true,
         (_, Type::Any) => true,
         (Type::Record(lhs), Type::Record(rhs)) | (Type::Table(lhs), Type::Table(rhs)) => {