Replace processor does not allow replacement: "" anymore

Hello,

It seems that starting from version 8.15, with the addition of the replace processor validation (Add config check to replace processor by fearful-symmetry · Pull Request #40047 · elastic/beats · GitHub), it is no longer possible to use an empty replacement value when trying to remove a string, as shown below:

 - replace:
        fields:
        - field: "myfield"
          pattern: "-"
          replacement: ""

This behavior change is not mentioned in the release notes, and after reviewing the code, it doesn't appear to be intentional.