(chocolatey#2510) Don't run beforemodify on non-windows

This sets the beforemodify script to only run on windows platforms.
The powershell scripts do not work on non-windows platforms, so they
should not be run.

src/chocolatey/infrastructure.app/services/ChocolateyPackageService.cs

@@ -814,10 +814,14 @@ public virtual ConcurrentDictionary<string, PackageResult> upgrade_run(Chocolate
 
         private void before_package_modify(PackageResult packageResult, ChocolateyConfiguration config)
         {
-            if (!config.SkipPackageInstallProvider)
+            if (!config.SkipPackageInstallProvider && config.Information.PlatformType == PlatformType.Windows)
             {
                 _powershellService.before_modify(config, packageResult);
             }
+            else
+            {
+                if (config.Information.PlatformType != PlatformType.Windows) this.Log().Info(ChocolateyLoggers.Important, () => " Skipping beforemodify Powershell script due to non-Windows.");
+            }
         }
 
         public void uninstall_noop(ChocolateyConfiguration config)