chore: Set CMake C++ standard to 20

[0ax1]

No description provided.

[codspeed-hq]

Merging this PR will improve performance by 17.62%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ 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

⚡ 3 improved benchmarks
✅ 2194 untouched benchmarks
⏩ 218 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	WallTime	arrow_checked_add_u32_avx2[16384]	21.4 µs	17.6 µs	+21.29%
⚡	WallTime	arrow_checked_add_u32_avx512[16384]	21.2 µs	17.6 µs	+20.69%
⚡	WallTime	mul_u32_nonnull_avx512	6.3 µs	5.7 µs	+11.17%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing ad/cxx20-cmake (0f1f976) with develop (ed4733f)}

Footnotes

1. 218 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩