fix: code-fence multichain network selector

[gantunesr]

Description

This change adds a multichain code fence to the getMultichainNetworkConfigurationsByChainId selector so the UI is not exposed to non-EVM network data from the multichain-network-controller

Related issues

Fixes: #30710

Manual testing steps

1. Build the extension Flask wallet and set the addSolanaAccount to true
2. You should see the Solana network in the network picker and use a Solana account
3. Remove the extension
4. Build the extension MetaMask wallet and set the addSolanaAccount to true
5. You should not see the Solana network in the network picker

Screenshots/Recordings

Before

Check issue #30710

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.

[metamaskbot]

Builds ready [4d2b915]

• builds: chrome, firefox
• builds (flask): chrome, firefox
• builds (MMI): chrome
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • content-script: 0
  • offscreen: 0

Page Load Metrics (1716 ± 123 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	317	2287	1625	374	180
		domContentLoaded	1416	2272	1683	250	120
		load	1427	2318	1716	256	123
		domInteractive	24	121	46	28	13
		backgroundConnect	8	117	37	26	13
		firstReactRender	14	73	38	23	11
		getState	5	74	17	19	9
		initialActions	0	1	0	0	0
		loadScripts	1005	1706	1270	201	96
		setupStore	7	46	11	8	4
		uiStartup	1589	2647	1941	308	148

Bundle size diffs [🚀 Bundle size reduced!]

• background: 0 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: -191 Bytes (-0.00%)

[metamaskbot]

Builds ready [58acef8]

• builds: chrome, firefox
• builds (flask): chrome, firefox
• builds (MMI): chrome
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • content-script: 0
  • offscreen: 0

Page Load Metrics (1557 ± 96 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	1390	2280	1563	200	96
		domContentLoaded	1368	2206	1528	186	89
		load	1376	2279	1557	200	96
		domInteractive	23	79	39	21	10
		backgroundConnect	8	93	29	23	11
		firstReactRender	13	70	27	20	10
		getState	4	51	14	15	7
		initialActions	0	1	0	0	0
		loadScripts	994	1701	1137	154	74
		setupStore	7	53	15	14	7
		uiStartup	1582	2665	1770	245	117

Bundle size diffs [🚀 Bundle size reduced!]

• background: 0 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: -191 Bytes (-0.00%)

[ccharly]

LGTM + Tested.