Fix data update coordinator garbage collection

[epenet]

Proposed change

When unloading a config entry, coordinators are automatically "shut down" via

core/homeassistant/helpers/update_coordinator.py

Lines 126 to 127 in f9cc336

	if self.config_entry:
	self.config_entry.async_on_unload(self.async_shutdown)

The linked debouncer is also automatically "shut down" via

core/homeassistant/helpers/update_coordinator.py

Line 178 in f9cc336

self._debounced_refresh.async_shutdown()

However, the debouncer holds a hard reference to the coordinator via the coordinator function, both directly and via the HassJob wrapper

core/homeassistant/helpers/debounce.py

Lines 57 to 62 in f9cc336

	self._function = function
	if self._job is None or function != self._job.target:
	self._job = HassJob(
	function,
	f"debouncer cooldown={self.cooldown}, immediate={self.immediate}",
	)

These hard references prevent both the coordinator and the debouncer from being garbage collected.

Related to #137237

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
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• The code change is tested and works locally.
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[DCSBL]

LGTM, thanks!