Consistent tag and architecture platform

[timdinhdotcom]

I noticed that the tag dotnet:6 is an arm64 while dotnet:7 is an amd64. This could potentially causing issues for a lot of people. I proposed that we are consistent with the platform architecture. Therefore, dotnet:7 should be arm64 instead of amd64

[ashishdhingra]

@timdinhdotcom Please refer #1471 (comment). This is fixed.

@github-actions proposed-answer