Deprecate positional boolean arguments

[flying-sheep]

For reference: #1241

[flying-sheep]

Since Azure deletes logs for cancelled jobs for some braindead reason, I manually sat there and watched the logs to see what went wrong. This is the end of them:

tests/test_backed_sparse.py::test_reset_group PASSED                     [ 15%]
tests/test_backed_sparse.py::test_wrong_formats[h5ad] PASSED             [ 15%]
tests/test_backed_sparse.py::test_wrong_formats[zarr] PASSED             [ 15%]
tests/test_backed_sparse.py::test_anndata_sparse_compat[h5ad] PASSED     [ 15%]
tests/test_backed_sparse.py::test_anndata_sparse_compat[zarr] PASSED     [ 15%]
tests/test_backed_sparse.py::test_backed_sizeof[h5ad] PASSED             [ 15%]
tests/test_backed_sparse.py::test_backed_sizeof[zarr] PASSED             [ 15%]
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 96.95%
##[warning]Free memory is lower than 5%; Currently used: 97.98%
##[warning]Free memory is lower than 5%; Currently used: 97.98%
tests/test_backed_sparse.py::test_append_overflow_check[csr_matrix-zarr] 

so maybe test_append_overflow_check[csr_matrix-zarr] never completes?