Use psalm-var annotation and fix phpcs errors

Author: jmikola

src/Operation/Find.php

@@ -429,7 +429,7 @@ private function createQueryOptions(): array
         }
 
         if (! empty($this->options['modifiers'])) {
-            /** @var array|object */
+            /** @psalm-var array|object */
             $modifiers = $this->options['modifiers'];
             $options['modifiers'] = is_object($modifiers) ? document_to_array($modifiers) : $modifiers;
         }

src/Operation/FindAndModify.php

@@ -293,7 +293,7 @@ private function createCommandDocument(): array
         }
 
         if (isset($this->options['update'])) {
-            /** @var array|object */
+            /** @psalm-var array|object */
             $update = $this->options['update'];
             $cmd['update'] = is_pipeline($update) ? $update : (object) $update;
         }

src/functions.php

@@ -115,7 +115,8 @@ function document_to_array($document): array
         /* Nested documents and arrays are intentionally left as BSON. We avoid
          * iterator_to_array() since Document and PackedArray iteration returns
          * all values as MongoDB\BSON\Value instances. */
-        /** @var array */
+
+        /** @psalm-var array */
         return $document->toPHP([
             'array' => 'bson',
             'document' => 'bson',
@@ -249,7 +250,7 @@ function is_pipeline($pipeline): bool
         /* Nested documents and arrays are intentionally left as BSON. We avoid
          * iterator_to_array() since Document iteration returns all values as
          * MongoDB\BSON\Value instances. */
-        /** @var array */
+        /** @psalm-var array */
         $pipeline = $pipeline->toPHP([
             'array' => 'bson',
             'document' => 'bson',