Add workaround for uv bug

astral-sh/uv#6127

Resolving dependencies using Python 3.8 with:

```
uv lock -p python3.8
```

failed with:

```
Using CPython 3.8.18 interpreter at: /opt/hostedtoolcache/Python/3.8.18/x64/bin/python
  × No solution found when resolving dependencies for split (python_full_version == '3.9.*'):
  ╰─▶ Because only the following versions of rucio-clients{python_full_version >= '3.9'} are available:
          rucio-clients{python_full_version >= '3.9'}<=33.6.1
          rucio-clients{python_full_version >= '3.9'}>=34.0.0,<=34.6.0
          rucio-clients{python_full_version >= '3.9'}>=35.0.0
      and the current Python version (3.8.18) does not satisfy Python>=3.9,<4, we can conclude that rucio-clients{python_full_version >= '3.9'}>=33.6.0 is incompatible.
      And because galaxy:dev depends on rucio-clients{python_full_version >= '3.9'}>=33.6.0 and your project depends on galaxy:dev, we can conclude that your project's requirements are unsatisfiable.

```

See https://github.com/galaxyproject/galaxy/actions/runs/11639391248/job/32415501724

pyproject.toml

@@ -236,6 +236,7 @@ keep-runtime-typing = true
 
 [tool.uv]
 default-groups = []
+environments = ["python_full_version == '3.8'", "python_full_version >= '3.9'"]  # https://github.com/astral-sh/uv/issues/6127
 extra-index-url = ["https://wheels.galaxyproject.org/simple"]
 index-strategy = "unsafe-best-match"
 package = false