ARROW-18379: [Python] Change warnings to _warnings in _plasma_store_entry_point

[AlenkaF]

This PR resolves #14693.

[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

[AlenkaF]

Testing the process of closing GitHub issues with PRs that do not have Jira linked to them. Observing:

• The warning about opening an associated Jira issue will need to be removed (will open a Jira issue for it, if I do not find any existing).
• Should we prepend the number of the GitHub issue to the title? Or is the title enough?

[github-actions]

https://issues.apache.org/jira/browse/ARROW-18379

[AlenkaF]

Linked it to a Jira issue as this typo should be included in the first possible release.

[AlenkaF]

@milesgranger ming looking at this PR please? Just a small typo correction :)

[milesgranger]

Short and sweet! LGTM!

[ursabot]

Benchmark runs are scheduled for baseline = b1110ae and contender = 16ef5a8. 16ef5a8 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Finished ⬇️0.2% ⬆️0.0%] test-mac-arm
[Finished ⬇️0.0% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.28% ⬆️0.03%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 16ef5a83 ec2-t3-xlarge-us-east-2
[Finished] 16ef5a83 test-mac-arm
[Finished] 16ef5a83 ursa-i9-9960x
[Finished] 16ef5a83 ursa-thinkcentre-m75q
[Finished] b1110ae3 ec2-t3-xlarge-us-east-2
[Finished] b1110ae3 test-mac-arm
[Finished] b1110ae3 ursa-i9-9960x
[Finished] b1110ae3 ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java