Memory leak fix for light transitions

A memory leak issue in color transitions has been fixed.
This issue has been both spotted and solved by GitHub user @denisys16.
Thanks!

The issue resulted in heap memory being leaked on each color transition. Eventually, memory would run out, followed by a firmware crash reboot. This was especially noticable when using the random color effect, since that one performs color transitions all the time.

How to upgrade your device

The basic steps for upgrading are:

1. Upgrade ESPHome to 2024.10.0 or later;
2. Update your device configuration (see below);
3. Compile and upload the new firmware.

If you have used the example.yaml to create your configuration, then update the configuration package ref: to point to release/2025.3.0.

packages:
  bslamp2:
    url: https://github.com/mmakaay/esphome-xiaomi_bslamp2
    ref: release/2025.3.0 <--- update this one
    files:
      ...
      ...