No skolem info panic involving typed hole

The following program causes a No skolem info panic on GHC 9.0.1, 9.2.1, HEAD, but not on GHC 8.10.5.

{-# LANGUAGE DataKinds                #-}
{-# LANGUAGE GADTs                    #-}
{-# LANGUAGE PolyKinds                #-}
{-# LANGUAGE RankNTypes               #-}
{-# LANGUAGE StandaloneKindSignatures #-}
{-# LANGUAGE TypeApplications         #-}
{-# LANGUAGE TypeFamilies             #-}
{-# LANGUAGE TypeOperators            #-}

module Bug where

data Context where
  Extend :: forall k. Context -> Context

type (:*&) :: Context -> forall k -> Context
type ctx :*& k = Extend @k ctx

data Idx ctx where
  T :: Idx ctx -> Idx (ctx :*& l)

data Rn ctx1 ctx2 where
  U :: Rn ctx1 ctx2 -> Rn (ctx1 :*& l) (ctx2 :*& l)

rnRename :: Rn ctx1 ctx2 -> Idx ctx3 -> Idx ctx4
rnRename (U _ ) _ = T _
rnRename _      T = undefined

[1 of 1] Compiling Bug              ( src\Bug.hs, interpreted )
ghc.exe: panic! (the 'impossible' happened)
  (GHC version 9.0.1:
        No skolem info:
  [ctx4_aBB[sk:1]]

The program should be rejected, and the error given with GHC 8.10.5 seems perfect:

[1 of 1] Compiling Bug              ( src\Bug.hs, interpreted )

src\Bug.hs:26:17: error:
    • The constructor ‘T’ should have 1 argument, but has been given none
    • In the pattern: T
      In an equation for ‘rnRename’: rnRename _ T = undefined
   |
26 | rnRename _      T = undefined
   |                 ^

The issue seems to be related to the presence of a typed hole on the line prior to the bogus pattern match.