chore: bump version to 5.7.0

Author: alfetopito

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@cowprotocol/cow-sdk",
-  "version": "5.7.0-RC.0",
+  "version": "5.7.0",
   "license": "(MIT OR Apache-2.0)",
   "files": [
     "/dist"
@@ -100,4 +100,4 @@
     "typescript",
     "subgraph"
   ]
-}
+}