test_read_format_zip_ppmd8_aes256_streaming fails with 6 assertion
failures on systems without a crypto library (openssl/nettle/mbedtls)
because it tries to decrypt a pre-built encrypted zipx file without
checking crypto availability first.
Add the same guard used by the other encrypted zip tests in this file.
Signed-off-by: Jaipaul Cheernam <jaipaul.cheernam@est.tech>
