Add typehints to a collection map

We know what is going in now

src/Commands/StatusCommand.php

@@ -36,10 +36,10 @@ public function handle(): int
         }
 
         $onlyChecks = Str::of($only)->explode(',')
-            ->map(fn($check) => trim($check));
+            ->map(fn(string $check) => trim($check));
 
         $exceptChecks = Str::of($except)->explode(',')
-            ->map(fn($check) => trim($check));
+            ->map(fn(string $check) => trim($check));
 
         $problems = [];
         /** @var \UKFast\HealthCheck\HealthCheck $check */