### What changes were proposed in this pull request?
This patch upgrades cloudpickle to 1.0.0 version.
Main changes:
1. cleanup unused functions: 936f16fac8
2. Fix relative imports inside function body: 31ecdd6f57
3. Write kw only arguments to pickle: 6cb4718528
### Why are the changes needed?
We should include new bug fix like 6cb4718528, because users might use such python function in PySpark.
```python
>>> def f(a, *, b=1):
... return a + b
...
>>> rdd = sc.parallelize([1, 2, 3])
>>> rdd.map(f).collect()
[Stage 0:> (0 + 12) / 12]19/10/03 00:42:24 ERROR Executor: Exception in task 3.0 in stage 0.0 (TID 3)
org.apache.spark.api.python.PythonException: Traceback (most recent call last):
File "/spark/python/lib/pyspark.zip/pyspark/worker.py", line 598, in main
process()
File "/spark/python/lib/pyspark.zip/pyspark/worker.py", line 590, in process
serializer.dump_stream(out_iter, outfile)
File "/spark/python/lib/pyspark.zip/pyspark/serializers.py", line 513, in dump_stream
vs = list(itertools.islice(iterator, batch))
File "/spark/python/lib/pyspark.zip/pyspark/util.py", line 99, in wrapper
return f(*args, **kwargs)
TypeError: f() missing 1 required keyword-only argument: 'b'
```
After:
```python
>>> def f(a, *, b=1):
... return a + b
...
>>> rdd = sc.parallelize([1, 2, 3])
>>> rdd.map(f).collect()
[2, 3, 4]
```
### Does this PR introduce any user-facing change?
Yes. This fixes two bugs when pickling Python functions.
### How was this patch tested?
Existing tests.
Closes#26009 from viirya/upgrade-cloudpickle.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2bc3fff13b