Add Python 3.13 to metadata

[ndgrigorian]

This PR proposes adding Python 3.13 to the pyproject.toml metadata

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[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[coveralls]

coverage: 85.0% (+0.01%) from 84.989%
when pulling 3efdbb7 on add-python-3.13-to-metadata
into 775d0d3 on master.

[github-actions]

Array API standard conformance tests for dpctl=0.21.0dev0=py310h93fe807_39 ran successfully.
Passed: 1115
Failed: 6
Skipped: 119

[antonwolfy]

LGTM