A federal appeals court held Monday that it lacks jurisdiction to consider whether qualified immunity shields a DuPage County sheriff’s deputy from a lawsuit filed by the estate of a 17-year-old he shot to death.The 7th U.S. Circuit Court of Appeals declined to consider the merits of a ruling by U.S. District Judge Joan B. Gottschall that factual disputes about what happened the night Scott Kuschell killed Trevon Johnson prevented her from granting Kuschell’s motion for summary judgment.A panel of the 7th Circuit conceded …