add Props generic to ExportedHandler for ExecutionContext

[deathbyknowledge]

Adds a Props type parameter to the ExportedHandler types for ExecutionContext.

More context cloudflare/agents#501

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[deathbyknowledge]

I have read the CLA Document and I hereby sign the CLA

[codspeed-hq]

Merging this PR will degrade performance by 12.32%

⚡ 1 improved benchmark
❌ 1 regressed benchmark
✅ 68 untouched benchmarks
⏩ 129 skipped benchmarks¹

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

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	Encode_ASCII_32[TextEncoder][0/0/32]	3.4 ms	3 ms	+13.19%
❌	jsonResponse[Response]	37.6 µs	42.9 µs	-12.32%

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_{Comparing deathbyknowledge:props-type-parameter (404d283) with main (fd41c48)}

Footnotes

1. 129 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. ↩