The `no_passthrough` suite disables `featureFlagExtensionsApiSignatureValidation` so
`jstests/noPassthrough/extensions/*` can load their test-key-signed extensions on secure-mode
(release) builds. That override lived only under `TestData.setParameters`, which the shell
(`src/mongo/shell/servers.js`) applies to mongod{} but not mongos — mongos reads the separate `TestData.setParametersMongos`.