fix: Revert getBrc20Tokens to sequential call

[jordankzf]

🔘 PR Type

What kind of change does this PR introduce?

On a newly restored wallet, brcCoinsList will not be populated. As a such, the previous concurrent API calls will not be aware of owned ordinals which will cause no fiat value to be displayed for brc20 tokens. This PR will revert the concurrent calls to a sequential order, which has a slight speed impact, but will ensure that the fiat value will always be displayed.

• Bugfix
• Enhancement
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no API changes)
• Build related changes
• CI related changes
• Documentation content changes
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🔄 Changes

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[github-actions]

Test with build here: https://github.com/secretkeylabs/xverse-web-extension/actions/runs/7649852927