Regression from #71248:

I believe this pull may have caused errors on WebGL since it moves the `GLES_OVER_GL` guard. WebGL does not support texture swizzling per: https://registry.khronos.org/webgl/specs/latest/2.0/#5.19
so this is causing the following trace in Chrome:
```
WebGL: INVALID_ENUM: texParameter: invalid parameter name
```
and it quickly fills up the 256 log limit for the same message in WebGL.

This doesn't appear to be breaking anything asides from causing the numerous log messages.

_Originally posted by @jnlopar in https://github.com/godotengine/godot/issues/71248#issuecomment-1384768973_

CC @rsjtdrjgfuzkfg @clayjohn
Config *config = Config::get_singleton();
	r_gl_format = 0;
	Ref<Image> image = p_image;
	r_compressed = false;
	r_real_format = p_format;
	bool need_decompress = false;
	bool decompress_ra_to_rg = false;
	switch (p_format) {
		case Image::FORMAT_L8: {
#ifdef GLES_OVER_GL
			r_gl_internal_format = GL_R8;
			r_gl_format = GL_RED;
			r_gl_type = GL_UNSIGNED_BYTE;
#else
			r_gl_internal_format = GL_LUMINANCE;
			r_gl_format = GL_LUMINANCE;
			r_gl_type = GL_UNSIGNED_BYTE;
#endif
		} break;
		case Image::FORMAT_LA8: {
#ifdef GLES_OVER_GL
			r_gl_internal_format = GL_RG8;
			r_gl_format = GL_RG;
			r_gl_type = GL_UNSIGNED_BYTE;
#else
			r_gl_internal_format = GL_LUMINANCE_ALPHA;