chore(gas-fee-controller): replace Sinon with Jest fake timers

[cryptodev-2s]

Explanation

References

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

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Note

Low Risk
Test-only timing/mocking refactor plus dependency removal; production code paths are unchanged, with risk mainly limited to potential flaky/incorrect timer advancement in the updated tests.

Overview
Updates GasFeeController.test.ts to stop using sinon.useFakeTimers()/clock.tickAsync() and instead rely on Jest fake timers (jest.useFakeTimers, jest.advanceTimersByTimeAsync, jest.advanceTimersToNextTimerAsync) for polling and NetworkController provider initialization flows.

Removes the sinon devDependency (and lockfile entry) and drops the related ESLint suppression that was only needed for the Sinon-based import pattern.

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