[10.x] Add missing typehint to cache repository contract

[axlon]

Cache repositories support dynamically configuring the TTL when 'remembering' a value, but the interface currently doesn't make this clear. The following works just fine, but the IDE complains because \Closure isn't allowed according to the docs

use Illuminate\Contracts\Cache\Repository;
use Lcobucci\JWT\UnencryptedToken;

function getOrCreateJwt(Repository $cache)
{
    return $cache->remember(
       'my-jwt-token',
       fn (UnencryptedToken $token) => $token->claims()->get(RegisteredClaims::EXPIRATION_TIME),
       fn () => $this->generateJwtToken(),
    );
}