[SPARK-54431] Update integration-test-ubuntu-spark41 to use Spark 4.1.0-preview4-java21

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

This PR aims to update `integration-test-ubuntu-spark41` to use Spark `4.1.0-preview4-java21`.

### Why are the changes needed?

To have the latest Spark 4.1.0-preview4 Linux test coverage.

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

No.

### How was this patch tested?

Pass the CIs and check the log.
- https://github.com/apache/spark-connect-swift/actions/runs/19523789087/job/55892314005?pr=264
```
Starting spark service container
  /usr/bin/docker pull apache/spark:4.1.0-preview4-java21
  4.1.0-preview4-java21: Pulling from apache/spark
```

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

No.

Closes #264 from dongjoon-hyun/SPARK-54431.

Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: dongjoon-hyun

.github/workflows/build_and_test.yml

@@ -93,7 +93,7 @@ jobs:
       SPARK_REMOTE: "sc://localhost:15003"
     services:
       spark:
-        image: apache/spark:4.1.0-preview3-java21
+        image: apache/spark:4.1.0-preview4-java21
         env:
           SPARK_NO_DAEMONIZE: 1
         ports: