Remove ? operators from proc-macro generated code

[toyboot4e]

This is an internal clean up PR. Hopefully it can also improve the compile time a bit.

From Twitter:

• MiniJinja author said avoiding ? improved both the compile time and the runtime performances.
• dtolnay said they don't use ? operators in serde and serde-json "because it is too slow".
• serde has their own try! macro that avoids type conversion
• Relevant issue on the rust repo

[toyboot4e]

CI build time on Windows changed from 8m 45s to 8m 5s. I think it doesn't mean anything though -- maybe they were run on different machine?

[lenscas]

CI build time on Windows changed from 8m 45s to 8m 5s. I think it doesn't mean anything though -- maybe they were run on different machine?

I don't think you can use github actions to measure performance as it will probably have quite a bit of variance as it is running on a VM at best and there are probably quite a few other VM's running on the same actual hardware doing their own things