ci: the gate compiles on the image the release builder already uses - #8

issue in macSCPCoreTests.ConnectMainActorLivenessTests/awaitingTheConnectorDoesNotKeepTheMainActor()/ConnectMainActorLivenessTests.swift:410:6: Issue recorded | liveness: test1 ambient=3.641267292 seconds gap=21.005775833 seconds ceiling=4.0 seconds — NOT ASSERTED. The ambient control is above 0.5 seconds, so this run has not shown that the instrument can tell a block from its own scheduling noise, and the gap has no verdict to give. Measured over 10 ticks.

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/