Migrate to Isolated mode

Migrated to [isolated model](https://learn.microsoft.com/en-us/azure/azure-functions/migrate-dotnet-to-isolated-model) not only because of its benefits but also because in proc will lose support in [Nov 2026](https://azure.microsoft.com/en-us/updates?id=retirement-support-for-the-inprocess-model-for-net-apps-in-azure-functions-ends-10-november-2026)