Use modules_enabled.gen.h to improve inter dependency checks

- Fix build with gdscript module disabled. Fixes #31011.
- Remove unused `gdscript` compile option.
- Fix build with regex module disabled.
- Fix ImageLoaderSVG to forward declare thirdparty structs.

scene/resources/dynamic_font.cpp

@@ -28,8 +28,11 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
 
-#ifdef FREETYPE_ENABLED
+#include "modules/modules_enabled.gen.h"
+#ifdef MODULE_FREETYPE_ENABLED
+
 #include "dynamic_font.h"
+
 #include "core/os/file_access.h"
 #include "core/os/os.h"