fix: flatpak build failing due to too large icons

[achim-k]

Fixes #7854

When building for Flatpak, electron-builder (or rather app-builder-bin) creates a set of icons from the Mac icns file which includes a 1024x1024 sized icon. According to the Flatpak spec however, icons must not be larger than 512px. This is the reason why the Flatpak build fails e.g. with the following error:

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🦋 Changeset detected

Latest commit: b3f241d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
app-builder-lib	Patch
dmg-builder	Patch
electron-builder-squirrel-windows	Patch
electron-builder	Patch
electron-forge-maker-appimage	Patch
electron-forge-maker-nsis-web	Patch
electron-forge-maker-nsis	Patch
electron-forge-maker-snap	Patch

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