### Godot version

master [f7bc653cbe81018fe362472a0143b7153a52f929]

### System information

Arch Linux (GCC 13.2.1)

### Issue description

Output:

```
In file included from tests/test_main.cpp:118:
./tests/servers/rendering/test_shader_preprocessor.h: In function 'bool TestShaderPreprocessor::is_operator_char(unsigned char)':
./tests/servers/rendering/test_shader_preprocessor.h:55:34: error: variable 'const std::string operators' has initializer but incomplete type
   55 |         static const std::string operators = "<>=+-*/";
      |                                  ^~~~~~~~~
./tests/servers/rendering/test_shader_preprocessor.h:56:50: error: incomplete type 'std::string' {aka 'std::__cxx11::basic_string<char>'} used in nested name specifier
   56 |         return operators.find(c) != std::string::npos;
      |                                                  ^~~~
scons: *** [tests/test_main.linuxbsd.editor.dev.x86_64.san.o] Error 1
scons: building terminated because of errors.
```

### Steps to reproduce

Compile the project. Probably needs GCC 13.

### Minimal reproduction project

N/A
"  float test3 = 0.8;\n"
			"  float test4 = 2.9;\n"
			"  float tmp;\n"
			"  ACSWAP(0,2)\n"
			"  ACSWAP(1,3)\n"
			"  ACSWAP(0,1)\n"
			"  ACSWAP(2,3)\n"
			"  ACSWAP(1,2)\n"
			"}\n");
	String expected(
			"fragment() {\n"
			"  float test0 = 1.2;\n"
			"  float test1 = 0.34;\n"
			"  float test3 = 0.8;\n"
			"  float test4 = 2.9;\n"
			"  float tmp;\n"
			"  if(test0 > test2) { tmp = test2; test2 = test0; test0 = tmp; }\n"
			"  if(test1 > test3) { tmp = test3; test3 = test1; test1 = tmp; }\n"
			"  if(test0 > test1) { tmp = test1; test1 = test0; test0 = tmp; }\n"
			"  if(test2 > test3) { tmp = test3; test3 = test2; test2 = tmp; }\n"
			"  if(test1 > test2) { tmp = test2; test2 = test1; test1 = tmp; }\n"
			"}\n");
	String result;
	ShaderPreprocessor preprocessor;
	CHECK_EQ(preprocessor.preprocess(code, String("file.gdshader"), result), Error::OK);
	CHECK_SHADER_EQ(result, expected);
}
TEST_CASE("[ShaderPreprocessor] Undefined behaviour") {