Removed SDL_RenderGeometryRawFloat()

After discussion with @ocornut, SDL_RenderGeometryRaw() will take floating point colors and conversion from 8-bit color can happen on the application side.  We can always add an 8-bit color fast path in the future if we need it on handheld platforms.

If you need code to do this in your application, you can use the following:

int SDL_RenderGeometryRaw8BitColor(SDL_Renderer *renderer, SDL_Texture *texture, const float *xy, int xy_stride, const SDL_Color *color, int color_stride, const float *uv, int uv_stride, int num_vertices, const void *indices, int num_indices, int size_indices)
{
    int i, retval, isstack;
    const Uint8 *color2 = (const Uint8 *)color;
    SDL_FColor *color3;

    if (num_vertices <= 0) {
        return SDL_InvalidParamError("num_vertices");
    }
    if (!color) {
        return SDL_InvalidParamError("color");
    }

    color3 = (SDL_FColor *)SDL_small_alloc(SDL_FColor, num_vertices, &isstack);
    if (!color3) {
        return -1;
    }

    for (i = 0; i < num_vertices; ++i) {
        color3[i].r = color->r / 255.0f;
        color3[i].g = color->g / 255.0f;
        color3[i].b = color->b / 255.0f;
        color3[i].a = color->a / 255.0f;
        color2 += color_stride;
        color = (const SDL_Color *)color2;
    }

    retval = SDL_RenderGeometryRaw(renderer, texture, xy, xy_stride, color3, sizeof(*color3), uv, uv_stride, num_vertices, indices, num_indices, size_indices);

    SDL_small_free(color3, isstack);

    return retval;
}

Fixes https://github.com/libsdl-org/SDL/issues/9009

test/testcolorspace.c

@@ -388,7 +388,7 @@ static void DrawGradient(float x, float y, float width, float height, float star
     color[2] = max_color;
     color[3] = min_color;
 
-    SDL_RenderGeometryRawFloat(renderer, NULL, xy, xy_stride, color, color_stride, NULL, 0, num_vertices, indices, num_indices, size_indices);
+    SDL_RenderGeometryRaw(renderer, NULL, xy, xy_stride, color, color_stride, NULL, 0, num_vertices, indices, num_indices, size_indices);
 }
 
 static void RenderGradientDrawing(void)