Stop publishing to test.pypi.org

We don't do this any more, and the tokens we have set up can't do it.

Author: samuelhwilliams

.github/workflows/publish.yaml

@@ -64,10 +64,6 @@ jobs:
       id-token: write
     steps:
       - uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
-      - uses: pypa/gh-action-pypi-publish@ec4db0b4ddc65acdf4bff5fa45ac92d78b56bdf0 # v1.9.0
-        with:
-          repository-url: https://test.pypi.org/legacy/
-          packages-dir: artifact/
       - uses: pypa/gh-action-pypi-publish@ec4db0b4ddc65acdf4bff5fa45ac92d78b56bdf0 # v1.9.0
         with:
           packages-dir: artifact/