The scope <scope>provided</scope> gives you an opportunity to tell that the jar would be available at runtime, so do not bundle it. It does not mean that you do not need it at compile time, hence maven would try to download that.
Now I think, the below maven artifact do not exist at all. I tries searching google, but not able to find. Hence you are getting this issue.
Change groupId to <groupId>net.sourceforge.ant4x</groupId> to get the latest jar.
<dependency>
<groupId>net.sourceforge.ant4x</groupId>
<artifactId>ant4x</artifactId>
<version>${net.sourceforge.ant4x-version}</version>
<scope>provided</scope>
</dependency>
Another solution for this problem is:
Where http://localhost/repo is your local repo URL:
<repositories>
<repository>
<id>wmc-central</id>
<url>http://localhost/repo</url>
</repository>
<-- Other repository config ... -->
</repositories>