chore: bump project to php 8.5

src/BusProNet/Model/CrmAttributesResponse.php

@@ -90,15 +90,20 @@ class CrmAttributesResponse
         // a response the CRM sent no attributes in still has to flatten to an empty set
         foreach ($this->getAttributeGroups() ?? [] as $group) {
             /** @var CrmAttributeGroup $group */
-            if (false === isset($crmSelections[$group->getLabel()])) {
-                $crmSelections[$group->getLabel()] = [];
+            // The CRM may report a group without a label. PHP used to coerce that null
+            // to an empty string on its own; since 8.5 it deprecates it, so the same
+            // key is now formed explicitly and nothing about the result changes.
+            $label = $group->getLabel() ?? '';
+
+            if (false === isset($crmSelections[$label])) {
+                $crmSelections[$label] = [];
             }
             foreach ($group->getAttributes() ?? [] as $attribute) {
                 /** @var CrmAttribute $attribute */
                 if (false === $attribute->isSelected()) {
                     continue;
                 }
-                $crmSelections[$group->getLabel()][] = $attribute->getLabel();
+                $crmSelections[$label][] = $attribute->getLabel();
             }
         }