Private keys as Zero Hashes cause "Private Key is invalid"

[quiet-node]

Description

Currently, if a user doesn't provide enough 6 Private Keys in the .env, the program will fill out the constant PRIVATE_KEYS with zero hashes which will cause Private Key is invalid

Steps to reproduce

1. In .env, provide less than 6 private keys for the PRIVATE_KEYS attribute
2. Run npx hardhat test

Additional context

No response

Hedera network

mainnet, testnet, previewnet, other

Version

0.7

Operating system

macOS