### Godot version

v4.1.dev.custom_build.a7276f1ce

### System information

Win10, AMD 2600, GeForce GTX 1060, Vulkan API 1.3.205

### Issue description

I can't get correct color data from an array of source_color type.
The color data is saved as **Color** in the file:
`shader_parameter/palette = [Color (1, 0, 0, 1), Color (0, 1, 0, 1), Color (0, 0, 1, 1)]`
Shouldn't it be saved as PackedColorArray?


### Steps to reproduce

1.Declare an array of source_color type.
2.Set colors.

### Minimal reproduction project

[shadertest.zip](https://github.com/godotengine/godot/files/11246504/shadertest.zip)

if (tk.type == TK_COMMA) {
											decl.initializer.push_back(n);
											continue;
										} else if (!curly && tk.type == TK_PARENTHESIS_CLOSE) {
											decl.initializer.push_back(n);
											break;
										} else if (curly && tk.type == TK_CURLY_BRACKET_CLOSE) {
											decl.initializer.push_back(n);
											break;
										} else {
											if (curly) {
												_set_expected_error("}", ",");
											} else {
												_set_expected_error(")", ",");
											}
											return ERR_PARSE_ERROR;
										}
									}
									if (unknown_size) {
										decl.size = decl.initializer.size();
										constant.array_size = decl.initializer.size();
									} else if (decl.initializer.size() != constant.array_size) {
										_set_error(RTR("Array size mismatch."));
										return ERR_PARSE_ERROR;
									}
								}
								array_size = constant.array_size;
								ConstantNode *expr = memnew(ConstantNode);
								expr->datatype = constant.type;
								expr->struct_name = constant.type_str;