uncaught TypeError when trying to load digit string as a public key

[simonLeary42]

using phpseclib v3.0.43

phpseclib3\Crypt\PublicKeyLoader\PublicKeyLoader::load('123');

warning:

.../vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/Formats/Keys/JWK.php:53
Attempt to read property "keys" on int

exception:

TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given
.../phpseclib/phpseclib/phpseclib/Crypt/Common/Formats/Keys/JWK.php:53
.../phpseclib/phpseclib/phpseclib/Crypt/EC/Formats/Keys/JWK.php:46
.../phpseclib/phpseclib/phpseclib/Crypt/Common/AsymmetricKey.php:150
.../phpseclib/phpseclib/phpseclib/Crypt/PublicKeyLoader.php:39

similar to #2076. It seems stupid but the legacy codebase I inherited is checking if an SSH key is valid based on whether or not PublicKeyLoader::load throws an exception, with arbitrary user input.

[terrafrost]

Fixed by #2078