[SPARK-50211][PYTHON][CONNECT][TESTS] Skip FeatureTests if torch is n…

…ot installed

### What changes were proposed in this pull request?

This PR proposes to skip FeatureTests if torch is not installed

### Why are the changes needed?

If tourch isn't available, we should run the tests `FeatureTests `. That's an optional dependency.

To fix Python 3.13 build
https://github.com/apache/spark/actions/runs/11654255828/job/32447601706

### Does this PR introduce _any_ user-facing change?

No, test-only.

### How was this patch tested?

Manually tested.

### Was this patch authored or co-authored using generative AI tooling?

No

Closes apache#48743 from HyukjinKwon/SPARK-50211.

Authored-by: Hyukjin Kwon <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

python/pyspark/ml/tests/connect/test_legacy_mode_feature.py

@@ -26,7 +26,10 @@
 from pyspark.util import is_remote_only
 from pyspark.sql import SparkSession
 from pyspark.testing.connectutils import should_test_connect, connect_requirement_message
-
+from pyspark.ml.tests.connect.test_connect_classification import (
+    have_torch,
+    torch_requirement_message,
+)
 
 if should_test_connect:
     from pyspark.ml.connect.feature import (
@@ -196,8 +199,10 @@ def test_array_assembler(self):
 
 
 @unittest.skipIf(
-    not should_test_connect or is_remote_only(),
-    connect_requirement_message or "pyspark-connect cannot test classic Spark",
+    not should_test_connect or not have_torch or is_remote_only(),
+    connect_requirement_message
+    or torch_requirement_message
+    or "pyspark-connect cannot test classic Spark",
 )
 class FeatureTests(FeatureTestsMixin, unittest.TestCase):
     def setUp(self) -> None: