fix: RPC circuit breaker, simulation result caching, union-type decode, oversized tx warning - #888

Process completed with exit code 1.

AssertionError: expected undefined to be true // Object.is equality - Expected: true + Received: undefined ❯ src/tests/simulateTransactionCache.test.ts:160:23

AssertionError: expected undefined to be true // Object.is equality - Expected: true + Received: undefined ❯ src/tests/simulateTransactionCache.test.ts:100:22

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/