fix(durable-object): fix wrong return type on durable object alarm fn

[Darckfast]

The alarm fn, according to Cloudflare docs https://developers.cloudflare.com/durable-objects/api/alarms/#alarm, returns void, but the workers-rs was returning a Result<Response>, this fixes by changing the return type to Result<()>

Fixes #712

[codspeed-hq]

Merging this PR will degrade performance by 54.54%

⚠️ 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

❌ 2 regressed benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	e2e_time	40 ms	89 ms	-55.06%
❌	WallTime	worker_internal_time	40 ms	87 ms	-54.02%

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 Darckfast:fix-durable-object-alarm-return-type (4e86e28) with main (f20a87c)}