[Performance] Optimize rejectGeneratedStaticAssets

[gonzaloriestra]

Optimized rejectGeneratedStaticAssets in packages/theme/src/cli/utilities/asset-checksum.ts by replacing chained .filter().map() with a single for...of loop when building liquidAssetKeys, eliminating intermediate array allocations and extra iterations.

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PR created automatically by Jules for task 1343280872611196807 started by @gonzaloriestra

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