perf(server): optimize writing performance

[hubcio]

This commit optimizes the log writing process by removing the
stream_position() call, which uses lseek and negatively
impacts performance. Afterwards, the new implementation
directly updates the log file size using fetch_add, resulting
in a 40% performance improvement on writing (Linux).
On MacOS, degradation was not visible.

[coveralls]

Pull Request Test Coverage Report for Build 13337959792

Details

• 26 of 30 (86.67%) changed or added relevant lines in 10 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.01%) to 74.75%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
server/src/streaming/segments/logs/persister_task.rs	11	15	73.33%

Files with Coverage Reduction	New Missed Lines	%
server/src/streaming/segments/logs/persister_task.rs	1	50.32%
server/src/streaming/systems/personal_access_tokens.rs	1	77.52%

Totals
Change from base Build 13337166152:	0.01%
Covered Lines:	25243
Relevant Lines:	33770

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💛 - Coveralls