add missing primary key constraints

[ewdurbin]

addresses #7128

[ewdurbin]

generated SQL:

ALTER TABLE release_files ADD PRIMARY KEY (id);

ALTER TABLE release_dependencies ADD PRIMARY KEY (id);

ALTER TABLE roles ADD PRIMARY KEY (id);

UPDATE alembic_version SET version_num='b5bb5d08543d' WHERE alembic_version.version_num = '08aedc089eaf';

COMMIT;

[ewdurbin]

I've confirmed that this migration is rather quick, and syncs SQLAlchemy's view of the DB with reality, so I'm gonna go ahead and ship it.