I tried building latest main (a9900adc9e8586eeeabf3b2b4364a1c61bf42a26) with ghc-9.2 and I realise there is a build error in io-classes:stm, which I suppose is the reason why you dropped support

Configuring library 'strict-stm' for io-classes-1.8.0.0...
Preprocessing library 'strict-stm' for io-classes-1.8.0.0...
Building library 'strict-stm' for io-classes-1.8.0.0...
[1 of 7] Compiling Control.Concurrent.Class.MonadSTM.Strict.TArray ( strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TArray.hs, dist/build/strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TArray.o, dist/build/strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TArray.dyn_o )
[2 of 7] Compiling Control.Concurrent.Class.MonadSTM.Strict.TBQueue ( strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TBQueue.hs, dist/build/strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TBQueue.o, dist/build/strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TBQueue.dyn_o )

strict-stm/Control/Concurrent/Class/MonadSTM/Strict/TBQueue.hs:44:22: error:
   • Illegal equational constraint LazyTBQueue m ~ LazyTBQueue n
     (Use GADTs or TypeFamilies to permit this)
   • In the type signature:
       castStrictTBQueue :: LazyTBQueue m ~ LazyTBQueue n =>
                            StrictTBQueue m a -> StrictTBQueue n a
  |
44 | castStrictTBQueue :: LazyTBQueue m ~ LazyTBQueue n
   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^...
Error: [Cabal-7125]
Failed to build lib:strict-stm from io-classes-1.8.0.0 (which is required by test:fs-sim-test from fs-sim-0.3.1.0). See the build log above for details.

But this build error is arguably an io-classes bug that should be resolved in a patch to io-classes, either by fixing the build failure or having stricter base bounds to rule out ghc-9.2

Originally posted by @jorisdral in input-output-hk/fs-sim#101 (review)

This looks like indeed it should either be ruled out by updating the bound on base (and possibly others, see https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/libraries/version-history) or fixing the code to compile with 9.2.