[hooks/security] Streamline attributes default permission check. The current default permission on attributes delegates the check to the entity permission update policy. Since this is already checked it can be skipped. The equality comparison will work, even with a deserialized schema, because the default update perm is:: ('managers', ERQLExpression(Any X WHERE U has_update_permission X, X eid %(x)s, U eid %(u)s)) which will always be deserialized in this order (groups first). However this is a slight semantic change: entity type level 'update' permissions can now be effectively used to encode update-time rules if the default attribute permissions are used (before this change, the 'update' rules at entity type level were fired at creation time). Closes #2930861.

[test/schemaserial] swap got/expected to get nicer unittest2 diagnostics Prepares #2965518.

[repository] drop safe attribute on ``internal_cnx`` People that need to disable hook can do it explicitly anyway.

[dbapi] deprecated the dbapi

[repoapi] deprecate dbapi compat method

[testlib] deprecated the older api to access the repo.

[connection] deprecated free_cnset and set_cnxset

[session] deprecate all Connection related method on session

[session] drop dead _current_cnx_id Not used anymore for a few commit.

[session] privatise get_cnx and close_cnx The only user, repoapi now use ``new_cnx``