audit(incentives): only distribute incentives to EOAs

[fedekunze]

Description

Closes: #XXX

This PR adds a safety check to only distribute incentives to EOAs (which should still be the case given that the EVM Hook in ApplyTransaction can only be called through a user-generated transaction to the EVM)

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• added a relevant changelog entry to the Unreleased section in CHANGELOG.md
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Code maintenance:

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• written unit and integration tests
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• confirmed the correct type prefix in the PR title
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[codecov]

Codecov Report

Merging #551 (8caacf1) into main (57dd8a2) will decrease coverage by 0.09%.
The diff coverage is 66.66%.

❗ Current head 8caacf1 differs from pull request most recent head 6fd1e69. Consider uploading reports for the commit 6fd1e69 to get more accurate results

@@            Coverage Diff             @@
##             main     #551      +/-   ##
==========================================
- Coverage   83.35%   83.26%   -0.10%     
==========================================
  Files         114      115       +1     
  Lines        6322     6340      +18     
==========================================
+ Hits         5270     5279       +9     
- Misses        926      933       +7     
- Partials      126      128       +2     

Impacted Files	Coverage Δ
x/incentives/keeper/evm_hooks.go	83.78% <62.50%> (-5.88%)	⬇️
x/incentives/keeper/proposals.go	100.00% <100.00%> (ø)
x/erc20/keeper/migrations.go	66.66% <0.00%> (-33.34%)	⬇️
x/erc20/migrations/v2/migration.go	50.00% <0.00%> (ø)

[danburck]

LGTM 🔥

[Prosp3r]

All looks good