When encountering an unsupported GHC version, HLS should output the last supported GHC version

## Is your enhancement request related to a problem? Please describe.

I just tried using HLS in VS Code (via the Haskell extension) and got an error message saying, "ERROR Error: HLS does not support GHC 9.10.2 yet." Understandable, but it would be nice to know what version of GHC I _can_ use.

## Describe the solution you'd like

The error message should include the latest supported GHC version.

## Describe alternatives you've considered

Googling it which is annoying and not straightforward, since support for particular GHC versions depends on the version of HLS you're using, which you then have to look up as well, so you have to google how to do that, etc.

Start by tracing how the VS Code extension surfaces the HLS error for an unsupported GHC version, then identify where the supported-version information is available. Done means the error message names the latest supported GHC version; verify the wording through the relevant extension or integration tests.

Written by the indexing model from the issue text.