clippy: Uses .into() when .try_into() is infallible

[brooksprumo]

Problem

There are nightly clippy warnings that will prevent upgrading our stable Rust version¹.

For this PR, it's this one: https://rust-lang.github.io/rust-clippy/master/index.html#/try_into

Summary of Changes

Replaces .try_into() with .into().

Footnotes

1. Here's the build failure: https://buildkite.com/solana-labs/solana/builds/104503#018bd970-26af-4b69-9fbb-29dea2681e4e ↩

[codecov]

Codecov Report

Merging #34119 (1bc4ff6) into master (b4c652e) will increase coverage by 0.0%.
The diff coverage is 100.0%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #34119   +/-   ##
=======================================
  Coverage    81.9%    81.9%           
=======================================
  Files         816      816           
  Lines      219753   219752    -1     
=======================================
+ Hits       180001   180010    +9     
+ Misses      39752    39742   -10