fix: disable account syncing

[mathieuartu]

This PR disables account syncing.
The QA team found a critical bug that prevents us from being confident enough to release this feature now. We'll continue investigating and we'll re-enable when we're 100% confident about this.

Description

Related issues

Fixes:

Manual testing steps

1. No testing steps. Account syncing is disabled

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[matteoscurati]

LGTM

[metamaskbot]

Builds ready [83dc0bd]

• builds: chrome, firefox
• builds (beta): chrome
• builds (flask): chrome, firefox
• builds (MMI): chrome, firefox
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• code coverage: Report
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7
  • common: 0, 1, 10, 11, 12, 2, 3, 4, 5, 6, 7, 8, 9
  • content-script: 0
  • offscreen: 0
  • ui: 0, 1, 10, 11, 12, 2, 3, 4, 5, 6, 7, 8, 9

Page Load Metrics (2161 ± 193 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	410	2394	1923	533	256
		domContentLoaded	1645	3709	2127	400	192
		load	1657	3749	2161	402	193
		domInteractive	18	158	49	33	16
		backgroundConnect	8	122	39	32	16
		firstReactRender	82	377	148	80	38
		getState	6	89	27	26	12
		initialActions	0	1	0	0	0
		loadScripts	1151	2772	1571	311	149
		setupStore	11	94	37	27	13
		uiStartup	1903	4187	2499	465	223

Bundle size diffs [🚨 Warning! Bundle size has increased!]

• background: 155 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 0 Bytes (0.00%)