[Chore] Fix `azd provision` to honor stripe as optional.

[Dina Berry (MSFT)]

How do I provision in such as way that Stripe is optional? Without it, the provision fails.

(x) Failed: Container App: ca-stripe-vyc7ius4wwiya

ERROR: deployment failed: failing invoking action 'provision', error deploying infrastructure: deploying to subscription:

Deployment Error Details:
InvalidParameterValueInContainerTemplate: The following field(s) are either invalid or missing. Field 'configuration.secrets' is invalid with details: 'Invalid value: "stripe-public-key": Secret value and keyvaulturl cant be empty at same time'; Field 'configuration.secrets' is invalid with details: 'Invalid value: "stripe-secret-key": Secret value and keyvaulturl cant be empty at same time'; Field 'configuration.secrets' is invalid with details: 'Invalid value: "stripe-webhook": Secret value and keyvaulturl cant be empty at same time';.

TraceID: ec1ed82715e7823765e73d38564a974a

[Wassim Chegham]

One option to fix this issue is to update the Bicep template to avoid creating secrets if the env variables aren't set.

[Wassim Chegham]

From @sinedied:

[10:49 AM] Yohan Lasorsa
AFAIK, azd uses current exported env variables for deployment, and some of these values are used as parameters for the Bicep templates

[Dina Berry (MSFT)]

This fix as merged into main worked for me. Thank you.