Delete unreachable line in IterativeAlgorithm

[freddyaboulton]

Pull Request Description

Fixes #2338

The uncovered line originally mentioned in #2338 is now covered but there's still an uncovered line!

We previously check that all custom_hyperparameters are instances of skopt spaces:

for hyperparam_name_val in self._custom_hyperparameters.values():
    for _, hyperparam_val in hyperparam_name_val.items():
        if not isinstance(hyperparam_val, (Integer, Real, Categorical)):
            raise ValueError(
                "Custom hyperparameters should only contain skopt.Space variables such as Categorical, Integer,"
                " and Real!"
            )

So the else clause I'm deleting can't be changed.

---

After creating the pull request: in order to pass the release_notes_updated check you will need to update the "Future Release" section of docs/source/release_notes.rst to include this pull request by adding :pr:123.

[codecov]

Codecov Report

Merging #2464 (8b4a5bf) into main (cee8518) will increase coverage by 0.1%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##            main   #2464     +/-   ##
=======================================
+ Coverage   99.6%   99.6%   +0.1%     
=======================================
  Files        283     283             
  Lines      25488   25486      -2     
=======================================
- Hits       25385   25384      -1     
+ Misses       103     102      -1     

Impacted Files	Coverage Δ
...lml/automl/automl_algorithm/iterative_algorithm.py	100.0% <ø> (+0.9%)	⬆️

---

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[jeremyliweishih]

cool makes sense！

[angela97lin]

👍