Fix running functional tests with NumPy 2.2 (backport #1437)

[mergify]

testcase performs an if not check on annotations passed in asserts.

From NumPy 2.2 this raises an exception about ambiguous falseyness [1], so convert the array to a string when passing it as an annotation to get around this.

[1]: https://numpy.org/devdocs/release/2.2.0-notes.html#expired-deprecations

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This is an automatic backport of pull request #1437 done by Mergify.

[mergify]

This pull request has been removed from the queue for the following reason: checks failed.

The merge conditions cannot be satisfied due to failing checks:

• ❌ doc (docs)
• ❌ test (py311, mysql-file)
• 🛑 test (py311, mysql-file-sqlalchemy14)
• 🛑 test (py311, mysql-s3)
• 🛑 test (py311, mysql-swift)
• 🛑 test (py311, postgresql-file)
• 🛑 test (py311, postgresql-file-sqlalchemy14)
• 🛑 test (py311, postgresql-file-upgrade-from-4.5)
• 🛑 test (py311, postgresql-s3)
• 🛑 test (py311, postgresql-swift)
• 🛑 test (py39, mysql-file)
• 🛑 test (py39, mysql-file-sqlalchemy14)
• 🛑 test (py39, mysql-s3)
• 🛑 test (py39, mysql-swift)
• 🛑 test (py39, postgresql-file)
• 🛑 test (py39, postgresql-file-sqlalchemy14)
• 🛑 test (py39, postgresql-file-upgrade-from-4.5)
• 🛑 test (py39, postgresql-s3)
• 🛑 test (py39, postgresql-swift)

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[tobias-urdin]

Included in #1449