[12.x] Add validation for password_hash() failure in hashers

[imhayatunnabi]

The password_hash() function can return false on failure (invalid
parameters, memory exhaustion, etc.), but the make() methods in both
BcryptHasher and ArgonHasher only caught Error exceptions and didn't
validate the return value. This creates:

1. Type safety violation: Method signature indicates @return string
   but could return false
2. Security risk: If false is stored as a hash, it could lead to
   authentication issues
3. Silent failures: Failures would go unnoticed until unexpected
   behavior occurs

Changes

BcryptHasher.php:65-67

if ($hash === false) {
    throw new RuntimeException('Bcrypt hashing failed.');
}

ArgonHasher.php:70-72
if ($hash === false) {
    throw new RuntimeException('Argon2 hashing failed.');
}

[browner12]

https://www.php.net/manual/en/function.password-hash.php

as of PHP 8.0.0, the password_hash() function always returns a string, and throws an exceptions for any of these errors.

This smells of AI generated code...