Update JSON Schema to match new Terms

[acl-cqc]

Following #2309 and #2360, our impl Arbitrary for Term (and hence Type and others) generated instances that did not conform to the Hugr JSON schema. The ideal solution here is to update the schema.

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Further history: prior to #2412, we were roundtrip testing these non-schema-compliant instances, but not checking schema conformance.

#2412 changed so that our impl Arbitrarys generate only instances that do conform to the schema. However, this leads to several problems:

• Any other code/proptests using Arbitrary run only on Terms that conform to the old schema, a significant narrowing
• e.g. we no longer check that non-conforming instances roundtrip (we could check this without checking schema compliance)
• The restriction to schema-conforming instances is done via an inefficient (not recommended) prop_filter

Thus, if we can't update the JSON schema, we could still fix some of these problems, albeit requiring significant refactoring of the impl Arbitrarys / #[derive(Arbitrary)]s