The ST_DISTANCE function is not tech-preview

Author: leemthompo

docs/reference/query-languages/esql/_snippets/functions/layout/st_distance.md

@@ -30,8 +30,6 @@
 import org.elasticsearch.xpack.esql.core.util.SpatialCoordinateTypes;
 import org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper;
 import org.elasticsearch.xpack.esql.expression.function.Example;
-import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesTo;
-import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesToLifecycle;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.Param;
 
@@ -226,8 +224,6 @@ public void distancePointDocValuesAndSource(DoubleBlock.Builder results, int pos
 
     @FunctionInfo(
         returnType = "double",
-        preview = true,
-        appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.PREVIEW) },
         description = """
             Computes the distance between two points.
             For cartesian geometries, this is the pythagorean distance in the same units as the original coordinates.