test-qc: replace deprecated TypeInType for GHC 9.14 strict builds

Start in test/Main.hs, inside the existing GHC version CPP guard, and review the reported deprecated TypeInType warning. Run cabal test primitive:test:test-qc --test-show-details=direct with GHC 9.14.1 and -Werror. Done means the test suite compiles without the deprecation warning and all 385 tests pass, without suppressing warnings or removing cases.

On GHC 9.14.1, test-qc at 2fdb2a9786e4ec9c15185804d1378360f3fcd058 fails when built with -Werror:

test/Main.hs:14:14: error: [GHC-53692] [-Wdeprecated-flags, Werror=deprecated-flags]
    -XTypeInType is deprecated: use -XDataKinds and -XPolyKinds instead

Replacing that pragma inside its existing CPP guard fixes the build:

 #if __GLASGOW_HASKELL__ >= 805
 {-# LANGUAGE DerivingVia #-}
-{-# LANGUAGE TypeInType #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE PolyKinds #-}
 #endif

Before: test compilation fails. After: all 385 tests pass with -Werror, with no test cases removed and no additional warning suppression. Tested on Linux with Cabal 3.16.1.0 and this project configuration:

packages: .
with-compiler: ghc-9.14.1
index-state: 2026-09-12T04:56:46Z
optimization: 2
tests: True
benchmarks: False
constraints: base ==4.22.0.0, deepseq ==1.5.1.0,
             transformers ==0.6.1.2, template-haskell ==2.24.0.0,
             QuickCheck ==2.15.0.1
package primitive
  ghc-options: -Werror -optl-fuse-ld=lld

Run cabal test primitive:test:test-qc --test-show-details=direct with LLVM lld installed. The comparison used separate build directories and an initially empty separate Cabal store. No allow-newer was needed. I have not tested the pragma change across the older supported GHC versions.

We found this while checking the dependencies of our TLS application under a warning-fatal build policy. The latest published Primitive 0.9.1.0 also fails that policy on three deprecated mutable-array size primops. I see #434 already handles those library warnings on master with module-level -Wno-deprecations; that is separate from this remaining test warning. A release containing that work and this test fix would help us validate the published package's own suite. Happy to contribute the test-source change and supply the captured logs/plans.