ARROW-17030: [Python] Ensure that dtype mutation test works on s390x

[cpcloud]

No description provided.

[github-actions]

Thanks for opening a pull request!

If this is not a minor PR. Could you open an issue for this pull request on JIRA? https://issues.apache.org/jira/browse/ARROW

Opening JIRAs ahead of time contributes to the Openness of the Apache Arrow project.

Then could you also rename pull request title in the following format?

ARROW-${JIRA_ID}: [${COMPONENT}] ${SUMMARY}

or

MINOR: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - How to contribute patches

[github-actions]

https://issues.apache.org/jira/browse/ARROW-17030

[cpcloud]

The Travis CI job failed, but for reasons unrelated to this change (https://app.travis-ci.com/github/apache/arrow/jobs/576170885#L9607) and this change fixes the test it intends to.

[kou]

OK. Could you open a JIRA issue for it if it doesn't exist?

[kou]

@github-actions crossbow submit pandas

[github-actions]

Revision: 240a3f4

Submitted crossbow builds: ursacomputing/crossbow @ actions-8fc6a81307

Task	Status
test-conda-python-3.7-pandas-0.24
test-conda-python-3.7-pandas-latest
test-conda-python-3.8-pandas-latest
test-conda-python-3.8-pandas-nightly
test-conda-python-3.9-pandas-master

[cpcloud]

OK. Could you open a JIRA issue for it if it doesn't exist?

Done in https://issues.apache.org/jira/browse/ARROW-17031.

[kou]

+1

Thanks!