Add python 3.12 to metadata

[antonwolfy]

Currently python 3.12 is missing in a list of programming languages in the metadata wile packages with python 3.12 are available of PyPi and conda channel.

This PR proposes to include python 3.12 to the metadata.
Note it does not consider python 3.13, because the packages for python 3.13 will not be included in the upcoming release.

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[github-actions]

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

[github-actions]

Array API standard conformance tests for dpctl=0.19.0dev0=py310h93fe807_529 ran successfully.
Passed: 894
Failed: 2
Skipped: 118

[coveralls]

coverage: 88.224%. remained the same
when pulling 0286440 on add-py-3.12-to-metadata
into 0a9c725 on master.

[ndgrigorian]

LGTM!