fix(solid.js): update greetMsg signal getter

[escwxyz]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe: minor change to the template (App.tsx), it should use getMsg() instead of getMsg to get the latest state

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix: remove a typo, closes #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

Other information

[amrbashir]

Coud you add a change file in .changes folder like this one https://github.com/tauri-apps/create-tauri-app/blob/9f0b36e7eaf39d7bcafd79e4901eae2702c9f6db/.changes/deps.md?plain=1?

[amrbashir]

thank you