GH-14790: [Dev] Avoid extra comment with Closes issue id on PRs

[raulcd]

Rationale for this change

We are duplicating the Closes issue_id comment on PRs adding it to both the PR body and a comment. There was some discussion to remove it from the comment.

What changes are included in this PR?

Remove adding extra comment to PR and check whether Closes XXX was already added on the body instead of checking comment.

Are these changes tested?

Yes, I have tested on my fork, see this PR: raulcd#79

Are there any user-facing changes?

No

• Closes: [Dev] Improve the link script to avoid extra comment #14790

[github-actions]

• Closes: [Dev] Improve the link script to avoid extra comment #14790

[kou]

+1

[raulcd]

👍

[ursabot]

Benchmark runs are scheduled for baseline = 1951a1a and contender = 431785f. 431785f 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
[Failed ⬇️0.15% ⬆️0.62%] test-mac-arm
[Failed ⬇️0.0% ⬆️11.89%] ursa-i9-9960x
[Failed ⬇️0.54% ⬆️0.09%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 431785f3 ec2-t3-xlarge-us-east-2
[Failed] 431785f3 test-mac-arm
[Failed] 431785f3 ursa-i9-9960x
[Finished] 431785f3 ursa-thinkcentre-m75q
[Finished] 1951a1ae ec2-t3-xlarge-us-east-2
[Finished] 1951a1ae test-mac-arm
[Finished] 1951a1ae ursa-i9-9960x
[Failed] 1951a1ae 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