Make IsNetFrameworkRuntime initializer less dangerous

[pardeike]

Harmony/Harmony/Tools/AccessTools.cs

Line 1649 in ad6eba6

TypeByName("System.Runtime.InteropServices.RuntimeInformation")?.GetProperty("FrameworkDescription")

Use

public static bool IsNetFrameworkRuntime { get; } = 
Type.GetType("System.Runtime.InteropServices.RuntimeInformation, mscorlib", throwOnError: false)
?.GetProperty("FrameworkDescription").GetValue(null, null).ToString().StartsWith(".NET Framework") 
?? IsMonoRuntime is false;

to not scan through assembly and possibly trigger code.