fix: truncate file when not appending in writeFile, closes #7973

[zh217]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

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

Original issue: #7973

[FabianLars]

Hey, thanks for contributing! 2 things before we can merge this:

1. I think this can be simplified by just using truncate()
2. We require all commits to be signed, here's a guide on how to set it up: https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

[zh217]

Thanks for the suggestion. It's now changed and signed.

[FabianLars]

Cool, thanks! One last thing i always forget myself is a changefile like this: https://github.com/tauri-apps/tauri/blob/dev/.changes/fix-ipc-payload.md - once that's added we can merge your PR :)

[FabianLars]

Thank you!