[4.3] fix: merge mistake for rector.php

[kenjis]

Description
I forgot to add it when merging.
Remove the line that was removed in develop.
It should be removed when merging, but maybe I did something wrong when resolving conflicts.

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide

[samsonasik]

TypedPropertyFromAssignsRector already enabled at develop

• #6979

so no need to skip it

[kenjis]

Yes, TypedPropertyFromAssignsRector should not be skipped.

Frankly, I am not sure why the line in skip was not deleted when I merged develop.
But in fact, the line is still there in 4.3, so I will remove it in this PR.