feat(overlay): add credentialless attribute for iframe

[hrynevychroman]

When using the WASM module to generate image previews, I faced some errors with showing iframe after setting this parameters to server inside vite.config.js

server: {
  headers: {
    'Cross-Origin-Embedder-Policy': 'require-corp',
    'Cross-Origin-Opener-Policy': 'same-origin',
  },
},

The fix for this was setting the credentialless attribute for all iframe; I think that we should add this to our overlay/iframe, too.

Chrome Blog: link

Video Example:
https://github.com/user-attachments/assets/2fbce091-91fd-4fad-a948-7e24f081a0a9

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[webfansplz]

Remove it temporarily because I found that adding it causes the localstorage state in the iframe to be isolated from the outside, causing some persistent state failures in the devtools client.

[sqcheah]

another thing to note is that it will cause the devtool fail to load in stackblitz playground

refer: stackblitz/webcontainer-core#1269
antfu's solution is to optionally allow iframe props: nuxt/devtools@0eb7a82

[webfansplz]

another thing to note is that it will cause the devtool fail to load in stackblitz playground

refer: stackblitz/webcontainer-core#1269 antfu's solution is to optionally allow iframe props: nuxt/devtools@0eb7a82

I think this is a better way to handle this case, PR Welcome.