Add types to consts

tests/Service/GeocodeTest.php

@@ -12,12 +12,12 @@ use Pcm\GeocodeBundle\Tests\AppKernel;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
 
 /**
- * Note we sleep 1s after requests to prevent breaking the API T&Cs
+ * We sleep 1 second after API calls to prevent breaking the API T&Cs.
  */
 class GeocodeTest extends KernelTestCase
 {
     // Buckingham Palace
-    private const POSTCODE = 'SW1A 1AA';
+    private const string POSTCODE = 'SW1A 1AA';
 
     private Geocoder $geocoder;
 
@@ -54,3 +54,4 @@ class GeocodeTest extends KernelTestCase
         };
     }
 }
+