feat: add new result_backend with capo-s3

[danfimov]

No description provided.

[codspeed]

Merging this PR will regress 1 benchmark

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 2 improved benchmarks
❌ 1 regressed benchmark
✅ 4 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	test_set_result	6.5 ms	7.5 ms	-13.88%
⚡	test_is_result_ready	6.5 ms	5.4 ms	+19.91%
⚡	test_get_result	6.7 ms	5.9 ms	+12.81%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing feat/capo-s3-result-backend (fabb605) with main (af34d48)}