Add support for Python 3.12 + Finish the migration to `pyproject.toml`

Closes !47, !56

Refs https://gitlab.teklia.com/workers/dan/-/merge_requests/197, https://gitlab.teklia.com/workers/spacy/-/merge_requests/111

nerval/cli.py

@@ -10,10 +10,10 @@ def threshold_float_type(arg):
     """Type function for argparse."""
     try:
         f = float(arg)
-    except ValueError:
-        raise argparse.ArgumentTypeError("Must be a floating point number.")
+    except ValueError as e:
+        raise argparse.ArgumentTypeError("Must be a floating point number.") from e
     if f < 0 or f > 1:
-        raise argparse.ArgumentTypeError("Must be between 0 and 1.")
+        raise argparse.ArgumentTypeError("Must be between 0 and 1.") from None
     return f