fix: set automatic slippage for swap transactions

[micaelae]

Description

This sets slippage to undefined when swapping in Solana. The bridge-api fetches quotes with an optimal slippage in this case

Related issues

Fixes: #30796

Manual testing steps

1. Open background logs
2. Fetch solana swap quotes
3. Check that there's no slippage passed to getQuote network call

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.

[metamaskbot]

Builds ready [f1b840c]

• 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, 14
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • content-script: 0
  • offscreen: 0

Page Load Metrics (2001 ± 75 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	518	2224	1843	457	219
		domContentLoaded	1734	2191	1953	145	70
		load	1748	2243	2001	157	75
		domInteractive	29	121	49	29	14
		backgroundConnect	14	123	52	27	13
		firstReactRender	15	75	35	19	9
		getState	6	70	24	19	9
		initialActions	0	1	0	0	0
		loadScripts	1305	1686	1499	122	59
		setupStore	8	61	19	16	8
		uiStartup	1996	2697	2297	194	93

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

• background: 0 Bytes (0.00%)
• ui: 30 Bytes (0.00%)
• common: 108 Bytes (0.00%)