Cleanup dependencies and BlockUtils

Author: JonasKunz

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/data/BlockUtils.java

@@ -303,12 +303,11 @@ yield new AggregateMetricDoubleLiteral(
                     aggBlock.countBlock().getInt(offset)
                 );
             }
-            case EXPONENTIAL_HISTOGRAM -> ExponentialHistogram.merge(
-                // TODO: do a cleaner copy with builder here
-                100,
-                ExponentialHistogramCircuitBreaker.noop(),
-                ((ExponentialHistogramArrayBlock) block).getExponentialHistogram(offset)
-            );
+            case EXPONENTIAL_HISTOGRAM -> {
+                ExponentialHistogram histogram = ((ExponentialHistogramArrayBlock) block).getExponentialHistogram(offset);
+                // return a copy so that the returned value is not bound to the lifetime of the block
+                yield ExponentialHistogram.builder(histogram, ExponentialHistogramCircuitBreaker.noop()).build();
+            }
             case UNKNOWN -> throw new IllegalArgumentException("can't read values from [" + block + "]");
         };
     }

x-pack/plugin/esql/qa/testFixtures/build.gradle

@@ -9,7 +9,6 @@ dependencies {
   implementation project(':client:rest')
   implementation project(':libs:logging')
   implementation project(':test:framework')
-  implementation project(":libs:exponential-histogram")
   api(testArtifact(project(xpackModule('esql-core'))))
   implementation project(':server')
   implementation "net.sf.supercsv:super-csv:${versions.supercsv}"