Bugfix: dot operation validation works for nullable types

The following template will now trigger two Errors:
```
{% types {
  foo: '?string',
  bar: '?\\Exception',
} %}
{{ foo.bad }}
{{ bar.bad }}
```

composer.json

@@ -8,7 +8,7 @@
             "name": "Jeroen Versteeg"
         }
     ],
-    "version": "1.0.4",
+    "version": "1.0.5",
     "autoload": {
         "psr-4": {
             "AlisQI\\TwigQI\\": "src/"

src/Inspection/InvalidDotOperation.php

@@ -94,6 +94,10 @@ private function checkOperation(string $name, string $attribute, NodeLocation $l
 
         $type = $variableTypeCollector->getDeclaredType($name);
 
+        if (str_starts_with($type, '?')) {
+            $type = substr($type, 1);
+        }
+
         if (in_array($type, self::UNSUPPORTED_TYPES)) {
             trigger_error(
                 sprintf('Invalid dot operation on unsupported type \'%s\' (at %s)', $type, $location),

tests/InvalidDotOperationTest.php

@@ -39,6 +39,9 @@ public static function getInvalidTypesForDotOperator(): array
             ['string'],
             ['number'],
             ['boolean'],
+            ['?string'],
+            ['?number'],
+            ['?boolean'],
         ];
     }
 
@@ -222,6 +225,23 @@ public function test_itValidatesDotOperationOnObjects(string $type, string $attr
         );
     }
 
+    /** @dataProvider getClassNamesAndAttributes */
+    public function test_itValidatesDotOperationOnObjectsEvenIfNullable(string $type, string $attribute, bool $isValid): void
+    {
+        $this->env->createTemplate(
+            <<<EOF
+            {% types {foo: '?$type'} %}
+            {{ foo.$attribute }}
+        EOF
+        );
+
+        self::assertEquals(
+            $isValid,
+            empty($this->errors),
+            implode(', ', $this->errors)
+        );
+    }
+
     public static function getAttributeShorthands(): array
     {
         $dummyClassFqn = '\\\\AlisQI\\\\TwigQI\\\\Tests\\\\Type\\\\Dummy';