### What changes were proposed in this pull request?
As title
### Why are the changes needed?
```shell
$ bin/spark-shell --master local[2]
23/07/06 16:11:30 WARN Utils: Set SPARK_LOCAL_IP if you need to bind to another address
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
23/07/06 16:11:40 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Spark context available as 'sc' (master = local[2], app id = local-1688631101733).
Spark session available as 'spark'.
Welcome to
____ __
/ __/__ ___ _____/ /__
_\ \/ _ \/ _ `/ __/ '_/
/___/ .__/\_,_/_/ /_/\_\ version 3.3.1
/_/
Using Scala version 2.12.15 (OpenJDK 64-Bit Server VM, Java 1.8.0_292)
Type in expressions to have them evaluated.
Type :help for more information.
scala> spark.sparkContext.getConf.get("spark.executor.cores")
java.util.NoSuchElementException: spark.executor.cores
at org.apache.spark.SparkConf.$anonfun$get$1(SparkConf.scala:245)
at scala.Option.getOrElse(Option.scala:189)
at org.apache.spark.SparkConf.get(SparkConf.scala:245)
... 47 elided
scala>
```
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
CelebornPipelineSortSuite should cover this change
Closes#1685 from cfmcgrady/local-core-number.
Authored-by: Fu Chen <cfmcgrady@gmail.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>
2bd1d86d41