duckdb: add release docs

[myrrc]

• Add release and upgrade docs for maintainers.
• Add object store auth section in user docs.

Resolves: #9487

[codspeed-hq]

Merging this PR will degrade performance by 11.6%

⚠️ 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.

❌ 2 regressed benchmarks
✅ 1979 untouched benchmarks
⏩ 54 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	words_gather_scalar_avx2[65536]	8.2 µs	9.4 µs	-11.8%
❌	Simulation	cold_misaligned[(16, 64)]	382.7 µs	431.9 µs	-11.4%

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 myrrc/duckdb-docs (bf28489) with develop (62648ef)}

Footnotes

1. 54 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. ↩