`dab-manifest.json` include previously used file identifiers and point to .net6

[seantleonard]

Why make this change?

• Add back <platform>-x64 file tag in the dab-manifest.json file (linux-x64, osx-x64, and win-x64)
  • This change will also maintain compat with SWA CLI: https://github.com/Azure/static-web-apps-cli/blob/0055b77b691704f0f383dce0498de851bb81e411/src/core/download-binary-helper.ts#L25
  • The following example is specifically linux but the file changes include all 3 platforms.

    {
    "files": {
    "linux-x64":{
        "url": "$($frameworkPlatformDownloadMetadata["net6.0_linux-x64"])",
        "sha": "$($frameworkPlatformFileHashMetadata["net6.0_linux-x64"])"
    },
    "linux-x64-net6":{
        "url": "$($frameworkPlatformDownloadMetadata["net6.0_linux-x64"])",
        "sha": "$($frameworkPlatformFileHashMetadata["net6.0_linux-x64"])"
    }
    }
    }

What is this change?

• 1.1.7 just has linux-x64-net6 and this update adds linux-x64 back to the list and points to .net6 dab binaries. (we'll need to update this by November in alignment with [.NET6 going out of support.](https://learn.microsoft.com/en-us/lifecycle/products/microsoft-net-and-net-core#:~:text=.NET%206.0%20(LTS,Nov%2012%2C%202024)

[seantleonard]

/azp run