[bug] iframe is too many nested with isolation pattern

[keiya01]

Describe the bug

I found the iframe element is too many nested with isolation pattern.
Is this behavior expected?

Reproduction

1. go to tauri repository
2. run cargo run --example isolation --features isolation
3. show inspector
4. see elements tab

Expected behavior

I think we should insert the only one iframe element.

Platform and versions

Environment
  › OS: Mac OS 12.3.1 X64
  › Node.js: 16.14.0
  › npm: 8.3.1
  › pnpm: Not installed!
  › yarn: 1.22.17
  › rustup: 1.24.3
  › rustc: 1.59.0
  › cargo: 1.59.0
  › Rust toolchain: stable-aarch64-apple-darwin 

Packages
  › @tauri-apps/cli [NPM]: 1.0.0-rc.9
  › @tauri-apps/api [NPM]: 1.0.0-rc.4
  › tauri [RUST]: 1.0.0-rc.8,
  › tauri-build [RUST]: 1.0.0-rc.7,
  › tao [RUST]: 0.8.2,
  › wry [RUST]: 0.15.0,

App
  › build-type: bundle
  › CSP: default-src 'self' customprotocol: asset:; font-src https://fonts.gstatic.com; img-src 'self' asset: https://asset.localhost blob: data:; style-src 'unsafe-inline' 'self' https://fonts.googleapis.com
  › distDir: ../dist
  › devPath: http://localhost:5000/
  › framework: Svelte

App directory structure
  ├─ isolation-dist
  ├─ dist
  ├─ node_modules
  ├─ public
  ├─ src-tauri
  └─ src

### Stack trace

_No response_

### Additional context

_No response_

[keiya01]

https://github.com/tauri-apps/wry/blob/fd1dcc3cc5a290bfe4ae8de04064074109902432/src/webview/wkwebview/mod.rs#L498-L500

I understand that this issue will be fixed when forMainFrameOnly is changed to true.

[keiya01]

I find the same issue in windows.

But linux seems to be working.

[lucasfernog]

I'm fixing it. Thanks for the report!