## What changes were proposed in this pull request?
Not a big deal but it bugged me. This PR removes printing out plans in PySpark UDF tests.
Before:
```
Running tests...
----------------------------------------------------------------------
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
== Parsed Logical Plan ==
GlobalLimit 1
+- LocalLimit 1
+- Project [id#668L, <lambda>(id#668L) AS copy#673]
+- Sort [id#668L ASC NULLS FIRST], true
+- Range (0, 10, step=1, splits=Some(4))
== Analyzed Logical Plan ==
id: bigint, copy: int
GlobalLimit 1
+- LocalLimit 1
+- Project [id#668L, <lambda>(id#668L) AS copy#673]
+- Sort [id#668L ASC NULLS FIRST], true
+- Range (0, 10, step=1, splits=Some(4))
== Optimized Logical Plan ==
GlobalLimit 1
+- LocalLimit 1
+- Project [id#668L, pythonUDF0#676 AS copy#673]
+- BatchEvalPython [<lambda>(id#668L)], [id#668L, pythonUDF0#676]
+- Range (0, 10, step=1, splits=Some(4))
== Physical Plan ==
CollectLimit 1
+- *(2) Project [id#668L, pythonUDF0#676 AS copy#673]
+- BatchEvalPython [<lambda>(id#668L)], [id#668L, pythonUDF0#676]
+- *(1) Range (0, 10, step=1, splits=4)
...........................................
----------------------------------------------------------------------
Ran 43 tests in 19.777s
```
After:
```
Running tests...
----------------------------------------------------------------------
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
...........................................
----------------------------------------------------------------------
Ran 43 tests in 25.201s
```
## How was this patch tested?
N/A
Closes#24661 from HyukjinKwon/remove-explain-in-test.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
20fb01bbea