BUG: use Python integers for repeat slice bounds

[Boulea7]

Summary

Closes #450. test_repeat now converts each array-valued repeat count to a Python integer before computing slice bounds. This keeps the value check compatible with libraries such as MLX that do not accept 0D arrays as slice indices.

Validation

• Reproduced the failure with an integer-convertible scalar that does not implement __index__, then confirmed the same path passes after the change
• ARRAY_API_TESTS_MODULE=array_api_strict .venv/bin/python -m pytest -q array_api_tests/test_manipulation_functions.py::test_repeat --max-examples=1000 --disable-deadline
• ARRAY_API_TESTS_MODULE=array_api_strict .venv/bin/python -m pytest -q meta_tests (70 passed, 1 skipped)
• .venv/bin/pre-commit run --all-files

The full manipulation test file also surfaced an unrelated test_reshape failure for an empty array with copy=False; the changed test_repeat passes independently.

[ev-br]

LGTM, thanks