Change altinn-env-events-fa functions to target dotnet 9

[SandGrainOne]

Description

We need to upgrade events function to target dotnet v9.0. This is important as some of the dependencies being updated leads to version conflicts.

An other important change is to have the functions run in isolated mode.

Tasks

• Update terraform scripts to enable dotnet 9 for the events functions
• Deploy the tf changes
• Change target framework for the Events functions project. Fix conflicts as they appear.
• Ensure that the functions are running in isolated mode.
• Update terraform scripts to ensure the function run in isolated mode. (If needed).
• Plan a controlled redeploy if necessary to avoid downtime.

Acceptance Criterias

• All functions are triggered correctly and run without issues in isolated mode.

[acn-sbuad]

Seems there still isn't support for cusom queue processor logic in Isolated workers ref Azure/azure-functions-dotnet-worker#382.
We cannot upgrade to isolated function until we get this support or a workaround. And as .net 8 is dependent on an isolated worker, this upgrade is blocked too.

[olebhansen]

Seems .net 8 now is supported in-process: Azure/azure-functions-host#9951

[cyptus]

nice but still we need a way to take control the queue parameters on function level to upgrade to isolated workers.

[olebhansen]

Do assesment if this is needed to retain support short term, or if we can refactor onto a service-bus implementation.