feat: update '@metamask/sdk' package to version '0.26.4'

[omridan159]

Description

Update the metamask-sdk package to version '0.26.4'

PLEASE NOTE- Checklist must be complete prior to review.

Checklist

• [x] Increment the version field in package.json of the package you have made changes in following semantic versioning and using alpha release tagging
• [x] Check the box that allows repo maintainers to update this PR
• [x] Test locally to make sure this feature/fix works
• [x] Run yarn check-all to confirm there are not any associated errors
• [x] Confirm this PR passes Circle CI checks
• [x] Add or update relevant information in the documentation

Docs Checklist

• [x] Include a screenshot of any changes (see docs README on running locally)
• [x] Add/update the appropriate package README (if applicable)
• [x] Add/update the related module in the docs demo (if applicable)
• [x] Add/update the related package in the docs/package.json file (if applicable)

If this PR includes changes to add an injected wallet or SDK wallet module:

Please complete the following using the internal demo package. To run this demo use the command yarn && yarn dev to get the project running at http://localhost:8080/

Tests with demo app (injected)

• [x] send transaction
• [x] switch chains
• [x] sign message
• [x] sign typed message
• [x] disconnect

Tests with demo app (SDK)

• [x] send transaction
• [x] switch chains
• [x] sign message
• [x] sign typed message
• [x] disconnect