v1.5.3 - safer connection teardown

Fluval BLE v1.5.3

v1.5.3 fixes two rare problems that could show up after the faster-startup
changes in v1.5.2: a Bluetooth proxy keeping a stale "listener" for the light,
and a light staying connected after a reload.

Fixed

• A stuck connection step is now ended the polite way. When a Bluetooth
  proxy was slow to answer the light, the integration used to give up by
  cancelling its own wait. With ESPHome proxies that can leave a stale listener
  behind until the proxy restarts. It now tells the proxy how long to wait
  (4 seconds for a subscribe, 8 seconds for a read), so the proxy cleans up
  after itself. The old 10-second cut-off stays only as a safety net.

• Reloading can no longer leave the light's connection open. If Home
  Assistant reloaded the integration (or you used fluvalble.release_link) at the
  moment a stuck connection was being dropped, the disconnect could be skipped.
  The light would then stay connected, which blocks the new copy of the
  integration and the Fluval phone app. Dropping a connection now always
  finishes, even if the task that started it is cancelled.

Notes

No settings, entities or actions changed.