ci: enable extra args for tests:run

This allows for (more) quickly checking a subset of tests in a matrix
run.

```
hatch run tests:run datalad_core/xxx/tests
```

pyproject.toml

@@ -76,7 +76,7 @@ template = "hatch-test"
 python = ["3.9", "3.10", "3.11", "3.12"]
 
 [tool.hatch.envs.tests.scripts]
-run = 'python -m pytest'
+run = 'python -m pytest {args}'
 
 [tool.hatch.envs.types]
 description = "type checking with MyPy"