remove redundant check

Author: not-napoleon

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/IgnoreNullMetrics.java

@@ -33,9 +33,6 @@
 public final class IgnoreNullMetrics extends Rule<LogicalPlan, LogicalPlan> {
     @Override
     public LogicalPlan apply(LogicalPlan logicalPlan) {
-        if (isMetricsQuery(logicalPlan) == false) {
-            return logicalPlan;
-        }
         Set<Attribute> metrics = collectMetrics(logicalPlan);
         if (metrics.isEmpty()) {
             return logicalPlan;

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/IgnoreNullMetricsTests.java

@@ -69,6 +69,7 @@ public void testSimple() {
         LogicalPlan actual = analyze("""
             TS test
             | STATS max(max_over_time(metric_1))
+            | LIMIT 10
             """);
         Limit limit = as(actual, Limit.class);
         Aggregate agg = as(limit.child(), Aggregate.class);