Use random8 for jellybean effect (#19418)

quantum/rgb_matrix/animations/jellybean_raindrops_anim.h

@@ -4,7 +4,7 @@ RGB_MATRIX_EFFECT(JELLYBEAN_RAINDROPS)
 
 static void jellybean_raindrops_set_color(int i, effect_params_t* params) {
     if (!HAS_ANY_FLAGS(g_led_config.flags[i], params->flags)) return;
-    HSV hsv = {rand() & 0xFF, qadd8(rand() & 0x7F, 0x80), rgb_matrix_config.hsv.v};
+    HSV hsv = {random8(), random8_min_max(127, 255), rgb_matrix_config.hsv.v};
     RGB rgb = rgb_matrix_hsv_to_rgb(hsv);
     rgb_matrix_set_color(i, rgb.r, rgb.g, rgb.b);
 }
@@ -13,7 +13,7 @@ bool JELLYBEAN_RAINDROPS(effect_params_t* params) {
     if (!params->init) {
         // Change one LED every tick, make sure speed is not 0
         if (scale16by8(g_rgb_timer, qadd8(rgb_matrix_config.speed, 16)) % 5 == 0) {
-            jellybean_raindrops_set_color(rand() % RGB_MATRIX_LED_COUNT, params);
+            jellybean_raindrops_set_color(random8_max(RGB_MATRIX_LED_COUNT), params);
         }
         return false;
     }