Refactor: Use sge.func for ML.DISTANCE (#2270)

Replaced `sge.Anonymous` with `sge.func` for `ML.DISTANCE` calls to
improve code clarity and consistency.

Thank you for opening a Pull Request! Before submitting your PR, there
are a few things you can do to make sure it goes smoothly:
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/python-bigquery-dataframes/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)

Fixes #<issue_number_goes_here> 🦕

Author: jialuoo

bigframes/core/compile/sqlglot/expressions/numeric_ops.py

@@ -127,14 +127,7 @@ def _(expr: TypedExpr) -> sge.Expression:
 
 @register_binary_op(ops.cosine_distance_op)
 def _(left: TypedExpr, right: TypedExpr) -> sge.Expression:
-    return sge.Anonymous(
-        this="ML.DISTANCE",
-        expressions=[
-            left.expr,
-            right.expr,
-            sge.Literal.string("COSINE"),
-        ],
-    )
+    return sge.func("ML.DISTANCE", left.expr, right.expr, sge.Literal.string("COSINE"))
 
 
 @register_unary_op(ops.exp_op)
@@ -307,13 +300,8 @@ def _(left: TypedExpr, right: TypedExpr) -> sge.Expression:
 
 @register_binary_op(ops.euclidean_distance_op)
 def _(left: TypedExpr, right: TypedExpr) -> sge.Expression:
-    return sge.Anonymous(
-        this="ML.DISTANCE",
-        expressions=[
-            left.expr,
-            right.expr,
-            sge.Literal.string("EUCLIDEAN"),
-        ],
+    return sge.func(
+        "ML.DISTANCE", left.expr, right.expr, sge.Literal.string("EUCLIDEAN")
     )