chore: update rust to 1.84 to unblock dependency upgrades

[mrgrain]

Fixes failing dependency upgrades.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.9%. Comparing base (50ddd9a) to head (82579d7).
Report is 1 commits behind head on main.

Additional details and impacted files

Components	Coverage Δ
Parser	87.2% <100.0%> (-6.7%)	⬇️
Intermediate Representation	93.9% <ø> (ø)
Synthesizers	95.8% <ø> (-<0.1%)	⬇️
Other	25.6% <ø> (-4.1%)	⬇️

@@           Coverage Diff           @@
##            main    #819     +/-   ##
=======================================
- Coverage   91.1%   90.9%   -0.2%     
=======================================
  Files         25      25             
  Lines       5202    5089    -113     
  Branches    5202    5089    -113     
=======================================
- Hits        4739    4625    -114     
- Misses       451     464     +13     
+ Partials      12       0     -12     

Files with missing lines	Coverage Δ
src/parser/lookup_table/mod.rs	100.0% <100.0%> (ø)

... and 8 files with indirect coverage changes

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