[ES|QL] Date nanos implicit casting in union types

docs/changelog/123678.yaml

@@ -0,0 +1,6 @@
+pr: 123678
+summary: Date nanos implicit casting
+area: ES|QL
+type: enhancement
+issues:
+ - 110009

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/FieldExtractorTestCase.java

@@ -959,6 +959,9 @@ public void testIntegerDocValuesConflict() throws IOException {
      * In an ideal world we'd promote the {@code integer} to an {@code long} and just go.
      */
     public void testLongIntegerConflict() throws IOException {
+        if (EsqlCapabilities.Cap.IMPLICIT_CASTING_UNION_TYPED_NUMERIC_AND_DATE.isEnabled()) {
+            return;
+        }
         assumeOriginalTypesReported();
         longTest().sourceMode(SourceMode.DEFAULT).createIndex("test1", "emp_no");
         index("test1", """
@@ -1002,6 +1005,9 @@ public void testLongIntegerConflict() throws IOException {
      * In an ideal world we'd promote the {@code short} to an {@code integer} and just go.
      */
     public void testIntegerShortConflict() throws IOException {
+        if (EsqlCapabilities.Cap.IMPLICIT_CASTING_UNION_TYPED_NUMERIC_AND_DATE.isEnabled()) {
+            return;
+        }
         assumeOriginalTypesReported();
         intTest().sourceMode(SourceMode.DEFAULT).createIndex("test1", "emp_no");
         index("test1", """