[release/9.1] Avoid setting --port twice for Azure Functions

[github-actions]

Backport of #7683 to release/9.1

/cc @captainsafia

Customer Impact

Our custom functions logic too eagerly set the --port argument if it was already configured in the command line arguments. This update changes the behavior to only set the port argument dynamically if it's not already defined.

Testing

Unit testing. Manual validation on Azure Functions playground app.

Risk

Low risk. --port is typially configured explicitly in the launchSettings by the default templates so the typical scenario is improved.

Regression?

No.

[eerhardt]

LGTM

[danmoseley]

Is this purely visual glitch or functional as well? The latter clearly meets bar

[captainsafia]

Is this purely visual glitch or functional as well? The latter clearly meets bar

There was no functional bug here, AFAIK. Previously, we would pass the --port argument twice to the underlying dotnet run command. When the functions host processed this, it would only accept the first argument.

Ensuring that we only pass the --port argument once is good hygeiene in case there are other components in the pipeline that don't make the same gurantees.

IMO, with this one impact/risk are minimal but it's fairly easy to fix so might as well.