Remove duckdb object cache

[myrrc]

We don't use it anyway as the right way is to use MultiFileSession
and get file footers out of it.

[codspeed-hq]

Merging this PR will degrade performance by 21.66%

⚠️ 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
❌ 3 regressed benchmarks
✅ 1192 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	10M_90%[10000000]	198.5 µs	226.5 µs	-12.36%
❌	WallTime	10M_10%[1000000]	133.5 µs	170.4 µs	-21.66%
⚡	WallTime	10M_50%[5000000]	192.3 µs	156.6 µs	+22.76%
❌	WallTime	dict[10M_u64_values_u8_codes]	217 µs	252.8 µs	-14.17%
⚡	WallTime	runend[10M_i32_runlen_100000]	130 µs	92.2 µs	+41.11%
⚡	Simulation	bitwise_not_vortex_buffer_mut[128]	275.3 ns	246.1 ns	+11.85%

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_{Comparing myrrc/duckdb-rm-cache (2e6b98d) with develop (deb7de0)}