fix typo in regex string

Author: tyrasd

data/fields/ref/FR/siret-FR.json

@@ -3,7 +3,7 @@
     "type": "identifier",
     "label": "SIRET Number",
     "urlFormat": "https://annuaire-entreprises.data.gouv.fr/etablissement/{value}",
-    "pattern": "^MONACO[A-Z\d]{5}001|\d{9}([1-7]\d{3}|0[1-9]\d{2}|00[1-9]\d|000[1-9])\d$",
+    "pattern": "^MONACO[A-Z\\d]{5}001|\\d{9}([1-7]\\d{3}|0[1-9]\\d{2}|00[1-9]\\d|000[1-9])\\d$",
     "locationSet": {
         "include": [
             "fr"