haddock test related failures with GHC 9.0.2 and 9.2.{1,2,3}

From https://github.com/haskell/cabal/pull/7952#issuecomment-1038742571

The following tests fail on GHC 9.0.2 (but not GHC 9.0.1) on both Linux and Mac

- PackageTests/Backpack/Includes2/setup-external.test.hs
- PackageTests/Backpack/Includes3/setup-external-ok.test.hs
- PackageTests/Backpack/Includes2/setup-per-component.test.hs

A failed run is https://github.com/haskell/cabal/runs/5178990935?check_suite_focus=true#step:10:1374

In all cases, the error happens while dealing with haddock. The relevant part of the log is:

```
Warning: The documentation for the following packages are not installed. No links will be generated to these packages: base-4.15.1.0, ghc-bignum-1.1, ghc-prim-0.7.0, Includes2-0.1.0.0
creating setup-per-component.dist/work/dist/doc/html/Includes2
/usr/local/.ghcup/ghc/9.0.2/bin/haddock-ghc-9.0.2 '@setup-per-component.dist/work/dist/doc/html/Includes2/haddock-response24859-1.txt'
0% ( 0 / 3) in 'Mine'
Missing documentation for:
Module header
Mine (mylib/Mine.hs:3)
mine (mylib/Mine.hs:4)
haddock: internal error: haddock:iface
CallStack (from HasCallStack):
error, called at utils/haddock/haddock-api/src/Haddock/Interface.hs:178:16 in main:Haddock.Interface
```