remove deleted keywords

src/analysis.zig

@@ -1764,14 +1764,10 @@ fn addOutlineNodes(allocator: *std.mem.Allocator, tree: ast.Tree, child: ast.Nod
         .@"while",
         .while_simple,
         .while_cont,
-        .true_literal,
-        .false_literal,
-        .null_literal,
         .@"defer",
         .@"if",
         .if_simple,
         .multiline_string_literal,
-        .undefined_literal,
         .@"anytype",
         .block,
         .block_semicolon,
@@ -3225,10 +3221,6 @@ fn makeScopeInternal(
         .char_literal,
         .integer_literal,
         .float_literal,
-        .false_literal,
-        .true_literal,
-        .null_literal,
-        .undefined_literal,
         .unreachable_literal,
         .@"continue",
         => {},

src/ast.zig

@@ -446,10 +446,6 @@ pub fn lastToken(tree: ast.Tree, node: ast.Node.Index) ast.TokenIndex {
         .char_literal,
         .integer_literal,
         .float_literal,
-        .false_literal,
-        .true_literal,
-        .null_literal,
-        .undefined_literal,
         .unreachable_literal,
         .identifier,
         .deref,

src/semantic_tokens.zig

@@ -107,7 +107,7 @@ const Builder = struct {
         // TODO More highlighting here
         const tok_id = tree.tokens.items(.tag)[tok];
         const tok_type: TokenType = switch (tok_id) {
-            .keyword_true, .keyword_false, .keyword_null, .keyword_undefined, .keyword_unreachable => .keywordLiteral,
+            .keyword_unreachable => .keywordLiteral,
             .integer_literal, .float_literal => .number,
             .string_literal, .multiline_string_literal_line, .char_literal => .string,
             .period, .comma, .r_paren, .l_paren, .r_brace, .l_brace, .semicolon, .colon => return,
@@ -770,12 +770,7 @@ fn writeNodeTokens(
 
             while (cur_tok <= last_tok) : (cur_tok += 1) try writeToken(builder, cur_tok, .string);
         },
-        .true_literal,
-        .false_literal,
-        .null_literal,
-        .undefined_literal,
-        .unreachable_literal,
-        => {
+        .unreachable_literal => {
             try writeToken(builder, main_token, .keywordLiteral);
         },
         .error_set_decl => {