build: use optional_dependencies (#177)

Signed-off-by: nstarman <nstarman@users.noreply.github.com>

pyproject.toml

@@ -30,6 +30,7 @@
     "jax",
     "jaxlib",
     "jaxtyping",
+    "optional_dependencies >= 0.1",
     "plum-dispatch>=2.5.1",
     "quax>=0.0.3",
     "quaxed >= 0.4",

src/coordinax/_interop/__init__.py

@@ -2,7 +2,7 @@
 
 __all__: list[str] = []
 
-from . import optional_deps
+from .optional_deps import OptDeps
 
-if optional_deps.HAS_ASTROPY:
+if OptDeps.ASTROPY.is_installed:
     from . import coordinax_interop_astropy  # noqa: F401

src/coordinax/_interop/optional_deps.py

@@ -1,7 +1,11 @@
 """Optional dependencies. Internal use only."""
 
-__all__ = ["HAS_ASTROPY"]
+__all__ = ["OptDeps"]
 
-from importlib.util import find_spec
+from optional_dependencies import OptionalDependencyEnum, auto
 
-HAS_ASTROPY: bool = find_spec("astropy") is not None
+
+class OptDeps(OptionalDependencyEnum):  # type: ignore[misc]
+    """Optional dependencies for ``coordinax``."""
+
+    ASTROPY = auto()