[FIX] attachment_indexation: avoid indexing attachment on copy

closes odoo/odoo#153422

X-original-commit: 0e268381ea7fde2154af8a4aadc4233f7eb2cec0
Signed-off-by: Raphael Collet <rco@odoo.com>

addons/attachment_indexation/models/ir_attachment.py

@@ -140,3 +140,7 @@ class IrAttachment(models.Model):
         if checksum:
             index_content_cache[checksum] = res
         return res
+
+    def copy(self, default=None):
+        index_content_cache[self.checksum] = self.index_content
+        return super().copy(default=default)