Add an unstable edition that includes all unreleased and upcoming encodings

[robert3005]

UNSTABLE exists to aggregate all core encodings that are in the works and should
be tested and benchmarked but not written by default writer

[codspeed]

Merging this PR will degrade performance by 5.26%

⚠️ 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.

⚠️ 16 benchmarks spent significant time in system calls

System calls cannot be consistently instrumented, so they are not included in the measure, which understates the real cost. Please switch to the Walltime instrument to accurately measure system calls.

Measurement and system calls

• test_scan_filter[int]
• test_scan_filter[int_str]
• test_scan_filter[int_str_float]
• multipolygon_mixed_validity
• decompress[u16, (4000, 256)]
• zstd_compress_string
• test_scan[int_str]
• take_varbin
• pcodec_compress_f64
• density_sweep_dense_runs[0.001]
• …and 6 more

ℹ️ 40 benchmarks have no flame graph

The flamegraph could not be generated because we failed to resolve the symbols in the profiling trace. This happens when we fail to harvest information about language frames.

• test_repeated_scan_scalar_at[int_float]
• test_repeated_scan_scalar_at[int]
• test_scan_filter[int]
• test_repeated_scan_scalar_at[int_str]
• test_repeated_scan_scalar_at[int_str_float]
• test_scan_filter[int_str]
• test_repeated_scan_to_arrow_array[int]
• test_scan_filter[int_str_float]
• test_repeated_scan_to_arrow_array[int_float]
• test_scan_scalar_at[int]
• …and 30 more

⚡ 3 improved benchmarks
❌ 5 regressed benchmarks
✅ 2239 untouched benchmarks
⏩ 12 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	threshold_neon[80]	3.7 µs	5.4 µs	-32.22%
❌	WallTime	filter_neon[8]	861 ns	1,189 ns	-27.59%
❌	WallTime	threshold_neon[8]	1.4 µs	1.8 µs	-19.27%
❌	WallTime	filter_neon[64]	1.7 µs	2 µs	-16.02%
❌	WallTime	filter_neon[80]	2.6 µs	2.9 µs	-12.61%
⚡	Simulation	take_map[(0.1, 1.0)]	352.2 µs	221.2 µs	+59.22%
⚡	Simulation	take_map[(0.1, 0.5)]	182.6 µs	146.4 µs	+24.72%
⚡	Simulation	take_map[(0.1, 0.05)]	87 µs	77.4 µs	+12.42%

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 rk/unstabledeletions (0d13017) with develop (6eae823)}

Footnotes

1. 12 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. ↩