Blocklists have not been out long enough for anyone to have set
"allowlistFiles" in blocklist.json, so the compatibility shim was
protecting nobody. Removes the bound property, ManualAllowlist's
WarnOnDeprecatedKey, and the test pinning the null default.
The key now binds nowhere. JsonConfig ignores unknown keys, so a config
that still carries it loads fine and the setting is simply inert.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
6dcb59e00b