Attempt to fix logText progressive memory issue in LargeText.java

[kalindafab]

See (https://issues.jenkins.io/browse/JENKINS-75081)

Testing done

I tested this change by running a Jenkins pipeline that generates a large amount of log output.

Tested with 7GB logs: The logs streamed correctly without an OutOfMemoryError.
Tested with 10GB logs: The issue still occurs, showing the same large log behavior.
Heap memory usage monitored: Observed heap dump and confirmed the Jetty thread still holds logs in memory.
Manual verification: Accessed /logText/progressiveText API after each build and checked the response.
No automated tests added because this issue requires large-scale log generation that is difficult to replicate in unit tests.

Proposed changelog entries

• human-readable text

Improve /logText/progressiveText API to handle large logs more efficiently and reduce heap memory usage.
Stream log data in smaller chunks instead of loading large portions into memory at once.
Modify LargeText and AnnotatedLargeText to avoid excessive memory consumption for logs above 7GB.
Partial fix for heap exhaustion in large build logs; further improvements needed for logs exceeding 10GB.

The fix works for logs up to 7GB, but the issue still persists for logs over 10GB. I’d appreciate guidance on further improving memory handling in Jetty and any best practices for handling extremely large logs efficiently.

Looking forward to your feedback—thanks in advance! 🙌

Proposed upgrade guidelines

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