Fix deprecations

Author: kksandr7

src/Model/ApiResourceBase.php

@@ -71,7 +71,7 @@ public function setBaseUrl($baseUrl)
     /**
      * @inheritdoc
      */
-    public function offsetExists($offset)
+    public function offsetExists(mixed $offset): bool
     {
         return $this->hasProperty($offset);
     }
@@ -102,7 +102,7 @@ public function __isset($name) {
     /**
      * @inheritdoc
      */
-    public function offsetGet($offset)
+    public function offsetGet(mixed $offset): mixed
     {
         return $this->getProperty($offset, false);
     }
@@ -125,7 +125,7 @@ public function __set($name, $value)
      *
      * @throws \BadMethodCallException
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet(mixed $offset, $value): mixed
     {
         throw new \BadMethodCallException('Properties are read-only');
     }
@@ -135,7 +135,7 @@ public function offsetSet($offset, $value)
      *
      * @throws \BadMethodCallException
      */
-    public function offsetUnset($offset)
+    public function offsetUnset(mixed $offset): void
     {
         throw new \BadMethodCallException('Properties are read-only');
     }