Fixes to make clippy version 1.80 happy

[taegyunkim]

What does this PR do?

Most of the changes are one of the following

1. Indentation for lists in docs -> fixed by adding a new line and/or spaces
2. Automatic checking of cfgs at compile-time -> fixed by adding check-cfg under [lints.rust.unexpected_cfgs] in Cargo.toml
3. allow(dead_code)

Motivation

Unblock CI for pending PRs

Additional Notes

Anything else we should know when reviewing?

How to test the change?

Describe here in detail how the change can be validated.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.46%. Comparing base (a2cd10a) to head (e8af88c).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #550      +/-   ##
==========================================
+ Coverage   70.45%   70.46%   +0.01%     
==========================================
  Files         213      213              
  Lines       28408    28425      +17     
==========================================
+ Hits        20014    20031      +17     
  Misses       8394     8394              

Components	Coverage Δ
crashtracker	25.21% <ø> (ø)
datadog-alloc	98.73% <ø> (ø)
data-pipeline	50.00% <ø> (ø)
data-pipeline-ffi	0.00% <ø> (ø)
ddcommon	86.43% <ø> (ø)
ddcommon-ffi	75.29% <ø> (ø)
ddtelemetry	58.95% <ø> (ø)
ipc	84.18% <100.00%> (+0.05%)	⬆️
profiling	78.09% <ø> (ø)
profiling-ffi	56.76% <ø> (ø)
serverless	0.00% <ø> (ø)
sidecar	35.42% <ø> (ø)
sidecar-ffi	0.00% <ø> (ø)
spawn-worker	54.98% <ø> (ø)
trace-mini-agent	71.14% <ø> (ø)
trace-normalization	98.24% <ø> (ø)
trace-obfuscation	95.73% <ø> (ø)
trace-protobuf	77.16% <ø> (ø)
trace-utils	91.03% <ø> (ø)

[pr-commenter]

Benchmarks

This comment was omitted because it was over 65536 characters.Please check the Gitlab Job logs to see its output.