Cannot update individual package version after commit `c82dd2e`

Starting from commit `c82dd2e` on 2026-06-07 I see the following error when updating the version of a single package (`ty` in this case) in the lock file:

```sh
❯ uv sync --all-extras -P ty
  × No solution found when resolving dependencies for split
    (markers: python_full_version >= '3.15' and sys_platform == 'win32'):
  ╰─▶ Because all versions of sphinxext-altair depend on your project and 
      altair[doc] depends on sphinxext-altair, we can conclude that altair[doc]
      depends on itself at an incompatible version (altair>=4.0.0).
      And because your project requires altair[doc], we can conclude that your
      project's requirements are unsatisfiable.

hint: While the active Python version is 3.12, the resolution failed for other 
Python versions supported by your project. Consider limiting your project's 
supported Python versions using `requires-python`.

hint: The package `sphinxext-altair` depends on the package `altair` but the name 
is shadowed by your project. Consider changing the name of the project.
```

Prior to this commit (`624bee9` on 2026-06-06), it was possible to upgrade the version of a single package:

```sh
❯ uv sync --all-extras -P ty
Resolved 179 packages in 110ms
Prepared 1 package in 0.68ms
Uninstalled 1 package in 1ms
Installed 1 package in 3ms
 - ty==0.0.42
 + ty==0.0.70
```

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