Fsdk,Fsdk.Tests(ArgsParsing): 2 more union cases #1594

Job	Run time
macOS--mono	7m 20s
linux-oldLTS-github--dotnet-and-msbuild	8m 32s
macOS--dotnet6-and-mono	11m 14s
linux-oldLTS-github--dotnet-and-xbuild	7m 20s
linux-newLTS-github--dotnet-and-xbuild	7m 55s
linux-oldLTS-vanilla--newmono	6m 40s
linux-oldLTS-vanilla--stockmono	7m 4s
linux-newLTS-github--dotnet-and-msbuild	8m 30s
linux-newLTS-vanilla--dotnet6	8m 15s
linux-newLTS-vanilla--newmono	8m 31s
linux-newLTS-vanilla--stockmono	5m 50s
windows--dotnet6	9m 33s
windows--legacyFramework	9m 14s
sanity-check	1m 32s
publish	59s
	1h 48m 29s

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