Warning too long for just the user of a package, reserve for `cabal check`

I am seeing a long warning about `cabal-version` as just the _user_ of a third-party package:
```
In order, the following will be built (use -v for more details):
- peano-0.1.0.1 (lib) (requires build)
- Agda-2.6.4 (lib:Agda, exe:agda, exe:agda-mode) (first run)
Configuring library for peano-0.1.0.1..
Warning: Packages using 'cabal-version: >= 1.10' and before 'cabal-version:
3.4' must specify the 'default-language' field for each component (e.g.
Haskell98 or Haskell2010). If a component uses different languages in
different modules then list the other ones in the 'other-languages' field.
Warning: For packages using 'cabal-version: >= 1.10' the 'extensions' field is
deprecated. The new 'default-extensions' field lists extensions that are used
in all modules in the component, while the 'other-extensions' field lists
extensions that are used in some modules, e.g. via the {-# LANGUAGE #-}
pragma.
```
I think a brief warning would be fine here, like:
```
Warning: Missing 'default-language' field.
```
The long warning with all the advice should be reserved for `cabal check`.