Revert "Move to modern upload URL away from legacy"

This reverts commit f8373e2.

The legacy URLs aren't actually deprecated, and they're what everyone
else still seems to be using.

Author: caleb531

.github/workflows/publish.yml

@@ -38,11 +38,11 @@ jobs:
     - name: Publish distribution to Test PyPI
       uses: pypa/gh-action-pypi-publish@release/v1
       with:
-        repository-url: https://test.pypi.org/
+        repository-url: https://test.pypi.org/legacy/
         attestations: false
 
     - name: Publish distribution to PyPI
       uses: pypa/gh-action-pypi-publish@release/v1
       with:
-        repository-url: https://upload.pypi.org/
+        repository-url: https://upload.pypi.org/legacy/
         attestations: false