Unable to start prometheus-exporter in 7x branch

Hi,
prometheus-exporter doesn't start in branch 7x on commit 7dfe1c093b65f77407c2df4c2a1120a213aef166, it does work on 26b498d0a9d25626a15e25b0cf97c8339114263a so something has changed between those two commits causing this.

I am presuming it is https://github.com/apache/lucene-solr/commit/e1eeafb5dc077976646b06f4cba4d77534963fa9#diff-3f7b27f0f087632739effa2aa508d77eR34

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/lucene/util/IOUtils
at org.apache.solr.core.SolrResourceLoader.close(SolrResourceLoader.java:881)
at org.apache.solr.prometheus.exporter.SolrExporter.loadMetricsConfiguration(SolrExporter.java:221)
at org.apache.solr.prometheus.exporter.SolrExporter.main(SolrExporter.java:205)
Caused by: java.lang.ClassNotFoundException: org.apache.lucene.util.IOUtils
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 3 more