fix: Rust v1.44 cargo fmt and clippy errors

[Wodann]

No description provided.

[baszalmstra]

👏

[codecov]

Codecov Report

Merging #214 into master will not change coverage.
The diff coverage is 95.55%.

@@           Coverage Diff           @@
##           master     #214   +/-   ##
=======================================
  Coverage   81.10%   81.10%           
=======================================
  Files         182      182           
  Lines       11903    11903           
=======================================
  Hits         9654     9654           
  Misses       2249     2249           

Impacted Files	Coverage Δ
crates/mun_syntax/src/syntax_kind/generated.rs	65.44% <95.53%> (ø)
crates/mun_hir/src/expr.rs	88.43% <100.00%> (ø)

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