Drop the SecureBackupSetupEntryPoint KDoc to match sibling entry points

No other FeatureEntryPoint interface carries KDoc, and the genericised
comment only restated what FeatureEntryPoint + DI already imply.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

features/securebackup/api/src/main/kotlin/io/element/android/features/securebackup/api/SecureBackupSetupEntryPoint.kt

@@ -12,12 +12,6 @@ import com.bumble.appyx.core.node.Node
 import io.element.android.libraries.architecture.FeatureEntryPoint
 import io.element.android.libraries.architecture.NodeInputs
 
-/**
- * Entry point for the recovery-key setup screen.
- *
- * The default implementation builds the standard auto-generated-key setup node. The binding can be
- * replaced to provide an alternative setup node.
- */
 interface SecureBackupSetupEntryPoint : FeatureEntryPoint {
     data class Inputs(val isChangeRecoveryKeyUserStory: Boolean) : NodeInputs