Multiple spaces in plugin parameter are reduced to 1 during prepare

### Affected version

3.3.1

### Bug description

I have a project where I have the antrun plugin generate a file.
One of the configuration parameters in that antrun is this:
``

The multiple spaces in the pathsep are needed as shown.
After doing a `mvn release:prepare` not only the version in the pom.xml has been updated but this line has been changed to where the multiple spaces have been replaced by a single space.

Start with the release:prepare entry point and inspect how it updates pom.xml, focusing on preservation of whitespace in the antrun plugin parameter. Reproduce the reported project configuration with multiple spaces in pathsep, then verify that release:prepare changes only the intended version fields and preserves the parameter spacing.

Written by the indexing model from the issue text.