fix(ramps): Set the region state from geolocation's response initially only

[imyugioh]

Explanation

Payment methods (getPaymentMethods) were being fetched redundantly from two paths: the controller's fireAndForget calls inside setSelectedToken and setSelectedProvider, and React Query independently in the mobile hook. This caused 2–3 duplicate API calls on every token selection, blocking the user with a ~10s spinner.

Changes:

1. setSelectedToken — Removed fireAndForget(getPaymentMethods(...)). Token selection now only updates tokens.selected and resets payment methods state. It no longer triggers a payment methods fetch; React Query on the mobile side is the single fetch owner.

2. setSelectedProvider — Removed fireAndForget(getPaymentMethods(...)) and the tokenSupportedByProvider gate that only existed to guard that call. Provider selection now only updates providers.selected and resets payment methods state. React Query on the mobile side handles fetching.

3. #runInit (geolocation fix) — forceRefresh no longer overrides a persisted userRegion with the geolocation endpoint response. Geolocation is only used to seed the initial region when userRegion is null, matching the agreed behavior: "once set, always respect the user's choice."

Link to metamask-mobile

TBD — mobile PR removes the duplicate React Query fetch trigger and scopes the query key to [regionCode, providerId] only.

References

TRAM-3398

Changelog

CHANGELOG entry: @metamask/ramps-controller — Removed redundant fireAndForget(getPaymentMethods) from setSelectedToken and setSelectedProvider; React Query is now the single fetch owner. Fixed init to not override persisted user region with geolocation on forceRefresh.

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them