fix: update poco version

Author: PierreJeanjacquot

package-lock.json

@@ -200,7 +200,7 @@
   "homepage": "https://github.com/iExecBlockchainComputing/iexec-sdk#readme",
   "dependencies": {
     "@ensdomains/ens-contracts": "^1.2.5",
-    "@iexec/poco": "^5.5.0",
+    "@iexec/poco": "^6.0.0",
     "@iexec/voucher-contracts": "^1.0.0",
     "@multiformats/multiaddr": "^12.4.0",
     "@types/bn.js": "^5.1.6",