is_tool_installed parsed `mongod --version` ("db version v8.0.15") into
"v8.0" because the leading v was left in place. It never equals the target
"8.0", so setup_mongodb always took the clean-upgrade path and purged
mongodb-org on every run. On Omada that also drags omadac out as a
reverse-dependency, wiping the controller.
Strip the v like the node and go branches already do, so an unchanged
version compares equal and setup_mongodb just updates in place.
dualfroz
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