Add migration for unique index in contacts

prisma/postgresql-migrations/20240811183328_add_unique_index_for_remoted_jid_and_instance_in_contacts/migration.sql

@@ -0,0 +1,8 @@
+/*
+  Warnings:
+
+  - A unique constraint covering the columns `[remoteJid,instanceId]` on the table `Contact` will be added. If there are existing duplicate values, this will fail.
+
+*/
+-- CreateIndex
+CREATE UNIQUE INDEX "Contact_remoteJid_instanceId_key" ON "Contact"("remoteJid", "instanceId");