Extra features with underscores in their names are not found when installing the test environment

[jeberger]

Given the following in my pyproject.toml:

[project.optional-dependencies]
foo_bar = [ "foo" ]

[tool.hatch.envs.hatch-test]
features = [
    "foo_bar",
]

Running hatch test causes the following error:

ValueError: Feature `foo-bar` of field `tool.hatch.envs.hatch-test.py3.11.features` is not defined in the dynamic field `project.optional-dependencies`

Replacing the underscores with hyphens (i.e. renaming foo_bar to foo-bar) works around the issue.

This used to work until v1.15.1, and fails since v1.16.0.