Update MSRV to 1.63

[alex]

No description provided.

[alex]

Hmm, the msrv job is failing, but I don't quite understand why.

[codspeed-hq]

CodSpeed Performance Report

Merging #4129 will degrade performances by 17.44%

_{Comparing alex:rm-parking-lot (fea5ddd) with main (6fb972b)}

Summary

❌ 1 regressions
✅ 68 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	alex:rm-parking-lot	Change
❌	drop_many_objects	55.2 µs	66.9 µs	-17.44%

[alex]

Woo! With enough elbow grease, got it working

[adamreichold]

LGTM except the one nit in the Event helper.

[alex]

Ok, should be good now.