refactor(stacktrace): remove unnecessary locking from segmentPrefixTrie

[kakkoyun]

What does this PR do?

Motivation

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• New code is free of linting errors. You can check this by running ./scripts/lint.sh locally.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.

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[kakkoyun]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• refactor(stacktrace): add captureStack helper for DRY capture logic #4151 : 2 dependent PRs (#4152 , #4153 )
• refactor(stacktrace): remove unused prefixTrie implementation #4150
• refactor(stacktrace): remove unnecessary locking from segmentPrefixTrie #4149 👈 (View in Graphite)
• perf(stacktrace): optimize parseSymbol with zero-allocation implementation #4148
• chore(stacktrace): Use internal/stacktrace package where it possible #4062
• main

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-11-20 13:54:41

Comparing candidate commit bf07665 in PR branch kakkoyun/11-20-stacktrace-optimize_parsesymbol_with_zero_allocation_implementation with baseline commit 89e0450 in branch graphite-base/4149.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 8 metrics, 0 unstable metrics.