SOLR-17481: Resolve use of -n flag in CLI commands

[epugh]

https://issues.apache.org/jira/browse/SOLR-17481

Description

Deal with overlaps in flags

Solution

deprecate (9x) and remove (10.0) -n for defining the number of threads in SolrExporter
Remove -n for no-prompt in RunExampleTool (this option is not supported via bin/solr or bin/solr.cmd so no need to deprecate).

Tests

Please describe the tests you've developed or run to confirm this patch implements the feature or solves the problem.

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide

[epugh]

@malliaridis this is ready for review. I just removed "n" from RunExampleTool since it is not exposed.

[malliaridis]

Thanks for providing a PR so quickly. :)

Additional occurences that should be updated:

• solr/solr-ref-guide/modules/deployment-guide/pages/monitoring-with-prometheus-and-grafana.adoc - ~6 occurences of -n for --num-threads
• solr/dev-tools/scripts/cloud.sh - may be ignored, but uses -n for number of nodes

[epugh]

Going to ignore cloud.sh since it doesn't have any long options... and I don't want to try to figure out adding long options!

[malliaridis]

Looks good to me then. :)