Update release workflow to use PyPI trusted publishing

[mattt]

Resolves #92

[mattt]

PyPI trusted functionality is currently limited to a closed beta testers' group. I've signed up for access using the form linked from pypi/warehouse#12965.

Holding as draft until this feature is available to us.

[mattt]

I haven't heard back from PyPI, but it appears that trusted publishing is now generally available.

[mattt]

Reverted by e7b3f9f

Failing run: https://github.com/replicate/replicate-python/actions/runs/6733395047/job/18302176951#step:7:16

Error: Trusted publishing exchange failure: 
Token request failed: the server refused the request for the following reasons:

* `invalid-publisher`: valid token, but no corresponding publisher (All lookup strategies exhausted)

This generally indicates a trusted publisher configuration error, but could
also indicate an internal error on GitHub or PyPI's part.


The claims rendered below are **for debugging purposes only**. You should **not**
use them to configure a trusted publisher unless they already match your expectations.

If a claim is not present in the claim set, then it is rendered as `MISSING`.

* `sub`: `repo:replicate/replicate-python:ref:refs/tags/0.15.6`
* `repository`: `replicate/replicate-python`
* `repository_owner`: `replicate`
* `repository_owner_id`: `60410876`
* `job_workflow_ref`: `replicate/replicate-python/.github/workflows/release.yaml@refs/tags/0.15.6`
* `ref`: `refs/tags/0.15.6`