Bump fabric-shim from 2.5.6 to 2.5.7 in /samples/node-contract

Bumps [fabric-shim](https://github.com/hyperledger/fabric-chaincode-node) from 2.5.6 to 2.5.7.
- [Release notes](https://github.com/hyperledger/fabric-chaincode-node/releases)
- [Changelog](https://github.com/hyperledger/fabric-chaincode-node/blob/main/CHANGELOG.md)
- [Commits](hyperledger/fabric-chaincode-node@v2.5.6...v2.5.7)

---
updated-dependencies:
- dependency-name: fabric-shim
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

samples/node-contract/package-lock.json

@@ -30,6 +30,6 @@
   },
   "dependencies": {
     "fabric-contract-api": "^2.5.6",
-    "fabric-shim": "^2.5.6"
+    "fabric-shim": "^2.5.7"
   }
 }