scripts,GitHubCI,Backend: add .NET6 snap #4092

Job	Run time
macOS--mono-only	11m 36s
windows--dotnet6-and-legacyFramework	6m 33s
linux-github--dotnet-and-newmono	7m 51s
linux-github--dotnet-and-mono	4m 57s
linux-vanilla--stockdotnet6-and-newmono	6m 24s
linux-vanilla--stockdotnet6-only	5m 29s
linux-vanilla--stockdotnet6-and-stockmono	7m 3s
linux-vanilla--stockmono-only	6m 12s
macOS--dotnet6-and-mono	13m 43s
macOS--dotnet6-only	7m 57s
windows--dotnet6-only	6m 1s
windows--legacyFramework-only	6m 31s
linux-vanilla--newmono-only	8m 53s
conventions	1m 40s
snap_pkg_mono	3m 4s
snap_pkg_beta	3m 47s
snap_pkg_dotnet	19s
	1h 48m 0s

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