fix: Stdcoroutine-5: Fix TSAN issues

[pratikmankawde]

Summary

• Drop UBSAN from TSAN builds: TSAN+UBSAN combined causes shadow memory collisions (immediate SEGV on the first test). UBSAN coverage is already provided by the ASAN+UBSAN configuration.
• Increase job timeout from 60 to 360 minutes for sanitizer builds (TSAN instrumentation runs ~10x slower).
• Clean tsan.supp: remove all rippled-code suppressions (races in our code should be fixed, not suppressed), keep only third-party/tooling suppressions (Boost, stdlib, TSAN internals).

Context

This is a child PR of #6429 (pratik/std-coro/cleanup-boost-coroutine).

The TSAN SEGV crashes were caused by combining TSAN and UBSAN in the same build — their shadow memory regions collide on large binaries like xrpld. Separating them resolves the immediate crash.

Test plan

• GCC-13 TSAN job passes (no SEGV, no data races)
• Clang-17 TSAN job passes (no SEGV, no data races)
• ASAN+UBSAN jobs still pass (unchanged)
• Non-sanitizer jobs unaffected

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (pratik/std-coro/cleanup-boost-coroutine@b53df32). Learn more about missing BASE report.

Additional details and impacted files

@@                            Coverage Diff                            @@
##             pratik/std-coro/cleanup-boost-coroutine   #6525   +/-   ##
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  Coverage                                           ?   81.4%           
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  Files                                              ?     998           
  Lines                                              ?   74511           
  Branches                                           ?    7564           
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  Hits                                               ?   60677           
  Misses                                             ?   13834           
  Partials                                           ?       0           

Files with missing lines	Coverage Δ
include/xrpl/core/CoroTaskRunner.ipp	89.5% <100.0%> (ø)
include/xrpl/core/JobQueue.h	90.9% <100.0%> (ø)

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