SOLR-18026 Fix failing test TestSolrCLIRunExample on java25

[janhoy]

Spent 1/2 hour with Claude on this, and it all makes sense.

Root Cause

The SOLR-15442 commit (which synchronized port and host variable naming) made an incomplete update:

1. What changed in SOLR-15442:
   • Renamed jetty.port → solr.port.listen
   • Renamed host → solr.host.advertise
   • Updated solr.xml to use ${solr.host.advertise:} instead of ${host:}
2. The bug:
   • TestSolrCLIRunExample.java was updated to use solr.port.listen ✅
   • But it still used the deprecated host property instead of solr.host.advertise ❌
   • TestHarness.java also still used the old host property ❌
3. Why it failed:
   • The test sets System.setProperty("host", "localhost") after EnvUtils initialization
   • The deprecated property mapping only runs during static initialization
   • So solr.host.advertise remained unset
   • Solr nodes couldn't register properly in ZooKeeper
   • Result: "No live SolrServers available to handle this request"

Files Fixed

1. TestSolrCLIRunExample.java (lines 127, 215, and JavaDoc):
   • Changed System.setProperty("host", "localhost")
   • To System.setProperty("solr.host.advertise", "localhost")
2. TestHarness.java (line 191):
   • Changed System.getProperty("host")
   • To System.getProperty("solr.host.advertise")

https://issues.apache.org/jira/browse/SOLR-18026

Other tests could also be at risk if they MODIFY the deprecated variant, and it is read by Solr with the new name.

[janhoy]

The unrelated precommit failure is due to a commit on SOLR-17928 yesterday, I left a note there...