[fix](case) test_delete_bitmap_metrics: warm agg cache on every replica

[shuke987]

Problem

test_delete_bitmap_metrics is flaky on the branch-4.1 P0 regression. It reads the per-replica aggregated delete-bitmap cache (/api/delete_bitmap/count_agg_cache) and asserts delete_bitmap_count == 8 on every replica of the tablet. But that agg cache is populated lazily, only on the replica that actually served a query. On a multi-replica cluster (force_olap_table_replication_num), the qt_sql select before the loop warms only one replica, so the other replicas still report 0 → the assertion fails. Which replica serves the query is non-deterministic → flaky.

Fix

Before the per-replica assertions, warm every replica by pinning the read to each replica ordinal (use_fix_replica) and running a select, so each replica's agg cache is populated. The assertions themselves are unchanged.

Verification

Reproduced and verified directly on a branch-4.1 cluster (force-3 replicas) via count_agg_cache:

• before any select: all replicas report agg=0
• after one default select: only the serving replica reports 8 (others 0)
• after warming all replicas: all report 8

The suite passes with the fix.

🤖 Generated with Claude Code

[hello-stephen]

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[shuke987]

run buildall