Cascade restriction attribute

[CBroz1]

• Adds line to solve Failure to cascade restriction with primary- followed by secondary-foreign-key inheritance #1159
• Adds test of edge case demonstrated in above issue
• Tests for cascading delete pass locally
• Pytests show unrelated errors related to an SSL certificate

WARNING urllib3.connectionpool:connectionpool.py:874 Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate has expired (_ssl.c:1002)'))': /datajoint.test

[dimitri-yatsenko]

This is a really good catch. Thank you.

[ethho]

Pytests show unrelated errors related to an SSL certificate

docker pull datajoint/nginx:latest before running tests should fix this. CI always pulls latest image, which is why this doesn't appear in GHA runs.