Fix failing test: sync CollectionObject expected errors in tests_legacy.py

[Copilot]

Fixes #8105

test_sqlalchemy_model_errors in tests_legacy.py was failing because the projects relationship on CollectionObject — the reverse relation of Project.collectionobjects ManyToManyField — was added to the SQLAlchemy model, but tests_legacy.py's expected_errors still listed it under not_found. tests.py had already been updated; tests_legacy.py had not.

Change

• tests_legacy.py: Remove "not_found": ["projects"] from the CollectionObject entry in expected_errors, bringing it in sync with tests.py:

# Before
"CollectionObject": {
    "not_found": ["projects"],
    "incorrect_direction": {"cojo": ["onetomany", "onetoone"]},
},

# After
"CollectionObject": {
    "incorrect_direction": {"cojo": ["onetomany", "onetoone"]},
},