drop benchmark modules from HLS example

hie-bios is failing to run the Cabal cradle for these, failing with the error
below:

```
> Build profile: -w ghc-8.10.4 -O1
> In order, the following will be built (use -v for more details):
>  - ghcide-0.7.5.0 (exe:ghcide-bench) (first run)
>  - ghcide-0.7.5.0 (bench:benchHist) (first run)
> Run the 'configure' command first.
> cabal: Failed to build exe:ghcide-bench from ghcide-0.7.5.0 (which is required
> by bench:benchHist from ghcide-0.7.5.0).
```

Author: pepeiborra

ghcide/bench/config.yaml

@@ -28,8 +28,6 @@ examples:
     modules:
         - hls-plugin-api/src/Ide/Plugin/Config.hs
         - ghcide/src/Development/IDE/Plugin/CodeAction/ExactPrint.hs
-        - ghcide/bench/hist/Main.hs
-        - ghcide/bench/lib/Experiments/Types.hs
         - ghcide/test/exe/Main.hs
         - exe/Plugins.hs