fix: update US origination #

[andrewleith]

Summary | Résumé

This updates the the env var AWS_US_TOLL_FREE_NUMBER to the correct origination number.

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[jimleroyer]

This is the toll free number for the staging environment. We think the lambda does not need that variable anyway, but we can slip in the update for now, to align it in production just in case.

[jimleroyer]

Let's wait before merging and see if we can get rid of this env var instead.