don't always aquite lock when calling RuntimeInformation.OSArchitecture and OSArchitecture.ProcessArchitecture

[adamsitnik]

[Benchmark]
public Architecture OSArchitecture() => RuntimeInformation.OSArchitecture;

[Benchmark]
public Architecture ProcessArchitecture() => RuntimeInformation.ProcessArchitecture;

BEFORE:

Method	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
OSArchitecture	16.202 ns	0.1181 ns	0.1105 ns	16.184 ns	16.073 ns	16.362 ns	-	-	-	-
ProcessArchitecture	16.221 ns	0.0320 ns	0.0267 ns	16.217 ns	16.180 ns	16.288 ns	-	-	-	-

AFTER:

Method	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
OSArchitecture	1.059 ns	0.0073 ns	0.0065 ns	1.059 ns	1.049 ns	1.070 ns	-	-	-	-
ProcessArchitecture	1.331 ns	0.0129 ns	0.0120 ns	1.328 ns	1.314 ns	1.354 ns	-	-	-	-

[Dotnet-GitSync-Bot]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[stephentoub]

Thanks :)

[adamsitnik]

@stephentoub thanks for another great review!