🐛 stats: optional optimizer argument in rv_continuous.fit() (#451)

* Make `optimizer` argument optional in `scipy.stats.rv_continuous.fit()`

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* Default to `...` instead of `None` in rv_continuous.fit()

Co-authored-by: Joren Hammudoglu <jhammudoglu@gmail.com>

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Joren Hammudoglu <jhammudoglu@gmail.com>

Author: 3 people

scipy-stubs/stats/_distn_infrastructure.pyi

@@ -805,7 +805,8 @@ class rv_continuous(_rv_mixin, rv_generic):
         optimizer: Callable[
             [_FloatND, tuple[float, ...], tuple[float, ...], bool],
             tuple[onp.ToFloat, ...],
-        ],
+        ]
+        | None = ...,
         method: _FitMethod = "MLE",
         **kwds: onp.ToFloat,
     ) -> tuple[_Float, ...]: ...