[SPARK-40022][YARN][TESTS] Ignore pyspark suites in `YarnClusterSuite…

…` when python3 is unavailable

### What changes were proposed in this pull request?
This pr adds `assume(isPythonAvailable)`  to `testPySpark` method in `YarnClusterSuite` to make `YarnClusterSuite` test succeeded in an environment without Python 3 configured.

### Why are the changes needed?
`YarnClusterSuite` should not `ABORTED` when `python3` is not configured.

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?

- Pass GitHub Actions
- Manual test

Run

```
mvn clean test -pl resource-managers/yarn -am -Pyarn -DwildcardSuites=org.apache.spark.deploy.yarn.YarnClusterSuite  -Dtest=none
```
in an environment without Python 3 configured:

**Before**

```
YarnClusterSuite:
org.apache.spark.deploy.yarn.YarnClusterSuite *** ABORTED ***
  java.lang.RuntimeException: Unable to load a Suite class that was discovered in the runpath: org.apache.spark.deploy.yarn.YarnClusterSuite
  at org.scalatest.tools.DiscoverySuite$.getSuiteInstance(DiscoverySuite.scala:81)
  at org.scalatest.tools.DiscoverySuite.$anonfun$nestedSuites$1(DiscoverySuite.scala:38)
  at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:286)
  at scala.collection.Iterator.foreach(Iterator.scala:943)
  at scala.collection.Iterator.foreach$(Iterator.scala:943)
  at scala.collection.AbstractIterator.foreach(Iterator.scala:1431)
  at scala.collection.IterableLike.foreach(IterableLike.scala:74)
  at scala.collection.IterableLike.foreach$(IterableLike.scala:73)
  at scala.collection.AbstractIterable.foreach(Iterable.scala:56)
  at scala.collection.TraversableLike.map(TraversableLike.scala:286)
  ...
Run completed in 833 milliseconds.
Total number of tests run: 0
Suites: completed 1, aborted 1
Tests: succeeded 0, failed 0, canceled 0, ignored 0, pending 0
*** 1 SUITE ABORTED ***
```

**After**

```
YarnClusterSuite:
- run Spark in yarn-client mode
- run Spark in yarn-cluster mode
- run Spark in yarn-client mode with unmanaged am
- run Spark in yarn-client mode with different configurations, ensuring redaction
- run Spark in yarn-cluster mode with different configurations, ensuring redaction
- yarn-cluster should respect conf overrides in SparkHadoopUtil (SPARK-16414, SPARK-23630)
- SPARK-35672: run Spark in yarn-client mode with additional jar using URI scheme 'local'
- SPARK-35672: run Spark in yarn-cluster mode with additional jar using URI scheme 'local'
- SPARK-35672: run Spark in yarn-client mode with additional jar using URI scheme 'local' and gateway-replacement path
- SPARK-35672: run Spark in yarn-cluster mode with additional jar using URI scheme 'local' and gateway-replacement path
- SPARK-35672: run Spark in yarn-cluster mode with additional jar using URI scheme 'local' and gateway-replacement path containing an environment variable
- SPARK-35672: run Spark in yarn-client mode with additional jar using URI scheme 'file'
- SPARK-35672: run Spark in yarn-cluster mode with additional jar using URI scheme 'file'
- run Spark in yarn-cluster mode unsuccessfully
- run Spark in yarn-cluster mode failure after sc initialized
- run Python application in yarn-client mode !!! CANCELED !!!
  YarnClusterSuite.this.isPythonAvailable was false (YarnClusterSuite.scala:376)
- run Python application in yarn-cluster mode !!! CANCELED !!!
  YarnClusterSuite.this.isPythonAvailable was false (YarnClusterSuite.scala:376)
- run Python application in yarn-cluster mode using spark.yarn.appMasterEnv to override local envvar !!! CANCELED !!!
  YarnClusterSuite.this.isPythonAvailable was false (YarnClusterSuite.scala:376)
- user class path first in client mode
- user class path first in cluster mode
- monitor app using launcher library
- running Spark in yarn-cluster mode displays driver log links
- timeout to get SparkContext in cluster mode triggers failure
- executor env overwrite AM env in client mode
- executor env overwrite AM env in cluster mode
- SPARK-34472: ivySettings file with no scheme or file:// scheme should be localized on driver in cluster mode
- SPARK-34472: ivySettings file with no scheme or file:// scheme should retain user provided path in client mode
- SPARK-34472: ivySettings file with non-file:// schemes should throw an error
Run completed in 7 minutes, 2 seconds.
Total number of tests run: 25
Suites: completed 2, aborted 0
Tests: succeeded 25, failed 0, canceled 3, ignored 0, pending 0
All tests passed.
```

Closes apache#37454 from LuciferYang/yarnclustersuite.

Authored-by: yangjie01 <yangjie01@baidu.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

resource-managers/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnClusterSuite.scala

@@ -55,11 +55,12 @@ import org.apache.spark.util.{Utils, YarnContainerInfoHelper}
 @ExtendedYarnTest
 class YarnClusterSuite extends BaseYarnClusterSuite {
 
-  private val pythonExecutablePath = {
+  private val (isPythonAvailable, pythonExecutablePath) = {
     // To make sure to use the same Python executable.
-    val maybePath = TestUtils.getAbsolutePathFromExecutable("python3")
-    assert(maybePath.isDefined)
-    maybePath.get
+    TestUtils.getAbsolutePathFromExecutable("python3") match {
+      case Some(path) => (true, path)
+      case _ => (false, "")
+    }
   }
 
   override def newYarnConfig(): YarnConfiguration = new YarnConfiguration()
@@ -372,6 +373,7 @@ class YarnClusterSuite extends BaseYarnClusterSuite {
       clientMode: Boolean,
       extraConf: Map[String, String] = Map(),
       extraEnv: Map[String, String] = Map()): Unit = {
+    assume(isPythonAvailable)
     val primaryPyFile = new File(tempDir, "test.py")
     Files.write(TEST_PYFILE, primaryPyFile, StandardCharsets.UTF_8)