(maint) fixup specs

These specs are related to no environment variable existing in Linux, so
it doesn't expand on mono for specs. It should match what we changed
the specs to use.

src/chocolatey.tests/infrastructure/commands/PowershellExecutorSpecs.cs

@@ -38,7 +38,7 @@ public override void Context()
         public class when_powershellExecutor_is_searching_for_powershell_locations_and_all_locations_exist : PowerShellExecutorSpecsBase
         {
             private string result = string.Empty;
-            private readonly string expected = Environment.ExpandEnvironmentVariables("%windir%\\SysNative\\WindowsPowerShell\\v1.0\\powershell.exe");
+            private readonly string expected = Environment.ExpandEnvironmentVariables("%systemroot%\\SysNative\\WindowsPowerShell\\v1.0\\powershell.exe");
 
             public override void Context()
             {
@@ -73,7 +73,7 @@ public void should_return_the_sysnative_path()
         public class when_powershellExecutor_is_searching_for_powershell_locations_there_is_no_sysnative : PowerShellExecutorSpecsBase
         {
             private string result = string.Empty;
-            private readonly string expected = Environment.ExpandEnvironmentVariables("%windir%\\System32\\WindowsPowerShell\\v1.0\\powershell.exe");
+            private readonly string expected = Environment.ExpandEnvironmentVariables("%systemroot%\\System32\\WindowsPowerShell\\v1.0\\powershell.exe");
 
             public override void Context()
             {