Drop support for building hie-compat with ghc-lib

Author: pepeiborra

.github/workflows/flags.yml

@@ -64,10 +64,6 @@ jobs:
       - name: Build `hls-graph` with flags
         run: cabal v2-build hls-graph --flags="embed-files stm-stats"
 
-      - if: matrix.ghc != '8.6.5' && matrix.ghc != '8.8.4'
-        name: Build `hie-compat` with flags
-        run: cabal v2-build hie-compat --flags="ghc-lib"
-
       - name: Build `ghcide` with flags
         run: cabal v2-build ghcide --flags="ghc-patched-unboxed-bytecode test-exe executable bench-exe"