Fix exception flow: omit if_has_tag when "restrict to same tag" is unchecked

[Copilot]

When creating an exception flow with "only sessions with this tag" unchecked, the generated rule included if_has_tag: null instead of omitting the field entirely, causing validation/matching issues.

Changes

• course/views.py: For both access and grading exception rules, conditionally include if_has_tag only when restricted_to_same_tag is True, rather than always emitting the key with a null value.

Before:

new_access_rule_json = {
    "permissions": [...],
    "if_has_tag": session.access_rules_tag if restricted_to_same_tag else None,
}

After:

new_access_rule_json = {
    "permissions": [...],
}
if restricted_to_same_tag:
    new_access_rule_json["if_has_tag"] = session.access_rules_tag

Same pattern applied to new_grading_rule_json.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• astral.sh
  • Triggering command: /usr/bin/curl curl -LsSf REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)