Two noPassthrough extension IFR-flag-retry tests assert $search/$vectorSearch-in-$unionWith metric deltas that don't hold in sharded clusters.

• vector_search_ifr_flag_retry.js (inUnionWithKickbackRetries): runUnionWithVectorSearchTests hardcodes the on-view $unionWith $vectorSearch kickback delta as 1 for every topology, but it is 1 in sharded and 0 in standalone, so the test failed in the standalone leg. Caused by recent view resolution changes.
• search_ifr_flag_retry_hybrid_search_flag_enabled.js (extensionSearchUsed): The test asserted exactly numNodes; but extensionSearchUsed counts per-node exec-stage builds, and a $unionWith subpipeline's merger placement varies run to run, so the sharded count is non-deterministically 1 or 2. Introduced by SERVER-128352.