Don't verify evictions in testFilterCacheStats (#42091)

If a background merge and refresh happens after a search but before a
stats query, then evictions will be non-zero.

Closes #32506

Author: dnhatn

server/src/test/java/org/elasticsearch/indices/stats/IndexStatsIT.java

@@ -919,7 +919,6 @@ public void testFilterCacheStats() throws Exception {
             IndicesStatsResponse stats = client().admin().indices().prepareStats("index").setQueryCache(true).get();
             assertCumulativeQueryCacheStats(stats);
             assertThat(stats.getTotal().queryCache.getHitCount(), equalTo(0L));
-            assertThat(stats.getTotal().queryCache.getEvictions(), equalTo(0L));
             assertThat(stats.getTotal().queryCache.getMissCount(), greaterThan(0L));
             assertThat(stats.getTotal().queryCache.getCacheSize(), greaterThan(0L));
         });
@@ -930,7 +929,6 @@ public void testFilterCacheStats() throws Exception {
             IndicesStatsResponse stats = client().admin().indices().prepareStats("index").setQueryCache(true).get();
             assertCumulativeQueryCacheStats(stats);
             assertThat(stats.getTotal().queryCache.getHitCount(), greaterThan(0L));
-            assertThat(stats.getTotal().queryCache.getEvictions(), equalTo(0L));
             assertThat(stats.getTotal().queryCache.getMissCount(), greaterThan(0L));
             assertThat(stats.getTotal().queryCache.getCacheSize(), greaterThan(0L));
         });