✨ Added Purch as vendor in callout-vendors.js

[bhuguet]

Added Purch in callout-vendors.js

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[bhuguet]

I signed it!

[googlebot]

CLAs look good, thanks!

[bhuguet]

Anyone for a review please ?

[Enriqe]

Adding @bradfrizzell who might know what to do with this PR 👍

[bradfrizzell]

@keithwrightbos to merge