ci: updates for Rust 1.77

[davidhewitt]

UI test updates for Rust 1.77

There are quite a few interesting detail additions here for the diagnostics. Maybe eventually we should try to simplify some of these messages by adjusting implementation details. For now I think this is fine.

[codspeed-hq]

CodSpeed Performance Report

Merging #3978 will improve performances by 26.94%

_{Comparing davidhewitt:rust-1.77 (5670357) with main (351c6a0)}

Summary

⚡ 1 improvements
✅ 66 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	davidhewitt:rust-1.77	Change
⚡	extract_str_extract_success	735.6 ns	579.4 ns	+26.94%

[davidhewitt]

For what it's worth, from the codspeed flame graph it looks like the performance win here can be attributed to better inlining on that particular benchmark.