Mark Style/HashExcept as unsafe

[r7kamura]

I think it would be better to assume that Style/HashExcept is unsafe because it detects and replaces even things that should not be replaced.

For example:

invalid_values = [3, 5]

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].each_slice(2).reject do |value1, _value2|
  invalid_values.include?(value1)
end
#=> [[1, 2], [7, 8], [9, 10]]

The above code is currently auto-corrected as follows:

invalid_values = [3, 5]

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10].each_slice(2).except(*invalid_values)
#=> undefined method `except' for #<Enumerator: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]:each_slice(2)> (NoMethodError)

---

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[koic]

Thanks!