Remove backward compatibility check in busy code for versions before 5.1.3 (2004)
The checks for backwards compatibility have on busy sites the highest hit rates of all entries in the util-memoize cache. Since we require the latest OpenACS 5.9.* for upgrade to 5.10, this can be removed (17 years later).
Comment deprecated proc, which was before defined as private, because of a false positive in acs-api-browser.callgraph__bad_library_calls: the "Authenticate" operation in the spec of auth::authentication::create_contract is mistakenly interpreted as the deprecated proc