feat[venom]: improve load elimination

[charles-cooper]

What I did

follow up to #4265 but generalize the lattice to multiple keys

How I did it

How to verify it

Commit message

Commit message for the final, squashed PR. (Optional, but reviewers will appreciate it! Please see our commit message style guide for what we would ideally like to see in a commit message.)

Description for the changelog

Cute Animal Picture

[codecov]

Codecov Report

Attention: Patch coverage is 8.51064% with 43 lines in your changes missing coverage. Please review.

Project coverage is 57.67%. Comparing base (db8dcc7) to head (55cbf90).

Files with missing lines	Patch %	Lines
vyper/venom/passes/load_elimination.py	8.88%	41 Missing ⚠️
vyper/venom/__init__.py	0.00%	2 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (db8dcc7) and HEAD (55cbf90). Click for more details.

HEAD has 31 uploads less than BASE

Flag	BASE (db8dcc7)	HEAD (55cbf90)
	141	110

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #4407       +/-   ##
===========================================
- Coverage   92.01%   57.67%   -34.35%     
===========================================
  Files         119      119               
  Lines       16692    16724       +32     
  Branches     2805     2812        +7     
===========================================
- Hits        15359     9645     -5714     
- Misses        915     6400     +5485     
- Partials      418      679      +261     

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