Add missing -o requirements.txt in uv pip compile example

[methane]

Summary

uv pip compile doesn't produce requirements.txt without -o requirements.txt option.

[zanieb]

Thanks!

[codspeed-hq]

Merging this PR will degrade performance by 6.79%

❌ 1 regressed benchmark
✅ 12 untouched benchmarks

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

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	wheelname_tag_compatibility[flyte-short-incompatible]	800.6 ns	858.9 ns	-6.79%

---

_{Comparing methane:patch-1 (9f3535d) with main (37c25f2)}