fix release pyiceberg-core to pypi

We made python publishing a "reusable workflow" and [part of publish.yml](https://github.com/apache/iceberg-rust/blob/4b0b35255469039d9877218049f93b07556124b5/.github/workflows/publish.yml#L72-L82)
Apparently this isnt a supported path for PyPi trusted publishing...

Ran into this in 0.9.1 release. Workaround is to run release_python.yml directly

```
##[debug]Authenticating to https://upload.pypi.org/legacy/ via Trusted Publishing
##[debug]Selected Trusted Publishing Exchange Endpoint: https://upload.pypi.org/_/Oidc/Mint-Token
Warning: Potential workflow misconfiguration:
The claims in this token suggest that the calling workflow is a reusable workflow.

In particular, this action was initiated by:

apache/iceberg-rust/.github/workflows/release_python.yml@refs/tags/v0.9.1-rc.2

Whereas its parent workflow is:

apache/iceberg-rust/.github/workflows/publish.yml@refs/tags/v0.9.1-rc.2

Reusable workflows are **not currently supported** by PyPI's Trusted Publishing
functionality, and are subject to breakage. Users are **strongly encouraged**
to avoid using reusable workflows for Trusted Publishing until support
becomes official. Please, do not report bugs if this breaks.
```

Compare .github/workflows/publish.yml, especially the referenced lines 72-82, with .github/workflows/release_python.yml and the direct-release workaround described in the issue. Start by checking how the Python package is sent to PyPI through Trusted Publishing, then verify a release path that publishes pyiceberg-core without the reported reusable-workflow warning.

Written by the indexing model from the issue text.