snapcraft.yaml,GitHubCI: snap pkg to ubuntu22.04 #2593

Job	Run time
linux20-github--dotnet-and-mono	5m 8s
linux20-github--dotnet-and-newmono	5m 20s
linux20-vanilla--newmono-only	9m 3s
linux20-vanilla--stockmono-only	6m 14s
linux22-github--dotnet-and-newmono	4m 36s
linux22-github--dotnet-and-mono	4m 54s
linux22-vanilla--newmono-only	7m 7s
linux22-vanilla--stockdotnet6-and-newmono	6m 25s
linux22-vanilla--stockdotnet6-and-stockmono	5m 32s
linux22-vanilla--stockmono-only	5m 42s
linux22-vanilla--stockdotnet6-only	7m 8s
macOS--dotnet6-and-mono	8m 29s
macOS--dotnet6-only	5m 44s
macOS--mono-only	8m 57s
windows--dotnet6-and-legacyFramework	10m 45s
windows--legacyFramework-only	15m 48s
windows--dotnet6-only	9m 12s
conventions	1m 26s
snap_pkg	6m 43s
	2h 14m 13s

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