refactor: extract getFieldValidationRules() for subclass override

Allow form component subclasses to filter or modify validation rules
before they are applied. FileUpload-based components need to strip
the 'string' rule that DatabaseFieldConstraints adds for string_value
columns, since FileUpload submits TemporaryUploadedFile objects.

Author: ManukMinasyan

src/Filament/Integration/Base/AbstractFormComponent.php

@@ -66,7 +66,7 @@ protected function configure(
                     filled($state)
             )
             ->required($this->validationService->isRequired($customField))
-            ->rules($this->validationService->getValidationRules($customField))
+            ->rules($this->getFieldValidationRules($customField))
             ->columnSpan($customField->width->getSpanValue())
             ->when(
                 FeatureManager::isEnabled(CustomFieldsFeature::FIELD_CONDITIONAL_VISIBILITY) &&
@@ -123,6 +123,12 @@ private function applyVisibility(
             : $field->live()->visibleJs($jsExpression);
     }
 
+    /** @return array<int, mixed> */
+    protected function getFieldValidationRules(CustomField $customField): array
+    {
+        return $this->validationService->getValidationRules($customField);
+    }
+
     /**
      * Apply settings dynamically to any Filament component
      */