Chore: cleanup clippy lints

[dsgallups]

I noticed that some of the tests weren't updated. Specifically this line:

        serialize_as!(struct_: Struct { key: "answer", val: (42, 42) }

missing structure fields:
- ser
- children
- write_indent
(rust-analyzer E0063)

This value may be found in many places, not sure what to do!

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 73.80952% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.54%. Comparing base (38b44d4) to head (a2eda8d).
⚠️ Report is 36 commits behind head on master.

Files with missing lines	Patch %	Lines
src/events/mod.rs	0.00%	8 Missing ⚠️
examples/flattened_enum.rs	0.00%	1 Missing ⚠️
src/events/attributes.rs	0.00%	1 Missing ⚠️
src/se/mod.rs	66.66%	1 Missing ⚠️
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #899      +/-   ##
==========================================
+ Coverage   55.52%   58.54%   +3.01%     
==========================================
  Files          42       42              
  Lines       15511    15173     -338     
==========================================
+ Hits         8613     8883     +270     
+ Misses       6898     6290     -608     

Flag	Coverage Δ
unittests	58.54% <73.80%> (+3.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[dsgallups]

note: the original comment at the top appears not to be caught by the checks. Not sure if that's something to consider..I don't quite know how to fix it, but it appears those structures are a bit out of date at this point.