DockerSwarmOperator: Support line breaks in service logs

[mr1holmes]

closes: #40571

---

Since we use splitlines() on the decoded log string,
If the log line is

b'2024-07-09T19:07:04.587918327Z \r  0%|          | 0/1000 [00:00<?, ?it/s]\r  0%|          | 1/1000 [00:00<01:40,  9.98it/s]

The stream_new_logs function treats it as three separate log lines, which leads to failure in finding timestamp in carriage return separated lines.

This PR changes the initial log pre-processing.
Since the log generator provided by docker's service_logs is already separating log lines we don't need to use splitlines().

[boring-cyborg]

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[mr1holmes]

Please review

[mr1holmes]

Please review

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.