Fix doNotDeploy not removing off-schedule BundleDeployments

[dockerized-nl]

Summary

• cleanupOrphanedBundleDeployments had a guard || bd.Spec.OffSchedule that preserved any BD with OffSchedule=true, even when that BD was no longer targeted (e.g. because doNotDeploy: true was set in fleet.yaml after the app was already deployed).
• This left the app installed on the downstream cluster indefinitely until the cluster re-entered its maintenance window — which could be days or weeks away.
• The fix removes the OffSchedule guard. The uidsToKeep set already correctly identifies all actively-targeted BDs; the extra guard was redundant for those and harmful for untargeted ones.

Root Cause

In cleanupOrphanedBundleDeployments (bundle_controller.go):

// Before — OffSchedule guard prevents deletion of untargeted BDs
return uidsToKeep.Has(bd.UID) || bd.Spec.OffSchedule

// After — only uidsToKeep determines what is kept
return uidsToKeep.Has(bd.UID)

slices.DeleteFunc removes elements where the predicate returns true, so any BD with OffSchedule=true was never added to the delete list — even when its cluster was no longer targeted at all.

Behaviour

Scenario	Before	After
doNotDeploy set, cluster in active window	BD deleted ✓	BD deleted ✓
doNotDeploy set, cluster in maintenance gap (OffSchedule=true)	BD not deleted ✗	BD deleted ✓
doNotDeploy not set, cluster in maintenance gap	BD kept ✓	BD kept ✓

Test plan

• Added integration test When("setting doNotDeploy after deployment when the existing BundleDeployment is off-schedule") that explicitly sets OffSchedule=true on the BD before enabling doNotDeploy, then asserts the BD is cleaned up.
• Existing doNotDeploy integration tests continue to pass.)

[kkaempf]

thanks @dockerized-nl, esp. for the extensive comments within the code 💚