[SPARK-33869][PYTHON][SQL][TESTS] Have a separate metastore directory for each PySpark test job

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

This PR proposes to have its own metastore directory to avoid potential conflict in catalog operations.

### Why are the changes needed?

To make PySpark tests less flaky.

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

No, dev-only.

### How was this patch tested?

Manually tested by trying some sleeps in #30873.

Closes #30875 from HyukjinKwon/SPARK-33869.

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

Author: HyukjinKwon

python/run-tests.py

@@ -83,12 +83,17 @@ def run_individual_python_test(target_dir, test_name, pyspark_python):
         tmp_dir = os.path.join(target_dir, str(uuid.uuid4()))
     os.mkdir(tmp_dir)
     env["TMPDIR"] = tmp_dir
+    metastore_dir = os.path.join(tmp_dir, str(uuid.uuid4()))
+    while os.path.isdir(metastore_dir):
+        metastore_dir = os.path.join(metastore_dir, str(uuid.uuid4()))
+    os.mkdir(metastore_dir)
 
     # Also override the JVM's temp directory by setting driver and executor options.
     java_options = "-Djava.io.tmpdir={0} -Dio.netty.tryReflectionSetAccessible=true".format(tmp_dir)
     spark_args = [
         "--conf", "spark.driver.extraJavaOptions='{0}'".format(java_options),
         "--conf", "spark.executor.extraJavaOptions='{0}'".format(java_options),
+        "--conf", "spark.sql.warehouse.dir='{0}'".format(metastore_dir),
         "pyspark-shell"
     ]
     env["PYSPARK_SUBMIT_ARGS"] = " ".join(spark_args)