chore: Reassign Wallet Integrations CODEOWNERS

[jiexi]

Explanation

Reassign Wallet Integrations CODEOWNERS to Mobile Platform (and Mobile Core UX)

References

Fixes: https://consensyssoftware.atlassian.net/browse/WAPI-1546

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, highlighting breaking changes as necessary
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

[adonesky1]

Lets hold off on removing ourselves for now since that will make merging PRs much more painful on this repo