Reverts "[skwasm] use temporary RawPaint objects (#54917)"

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Reverts: #54917

Initiated by: jonahwilliams

Reason for reverting: failing on framework -> engine roll https://ci.chromium.org/ui/p/flutter/builders/try/Linux%20web_skwasm_tests_7_last/10571/overview

Original PR Author: yjbanov

Reviewed By: {eyebrowsoffire}

This change reverts the following previous change:
Same as #54818, but for Skwasm.

Addresses the Paint issue in flutter/flutter#153678 in Skwasm

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