Make template package uninstallation detection report errors properly

Author: SteveSandersonMS

test/Templates.Test/Helpers/TemplatePackageInstaller.cs

@@ -74,23 +74,19 @@ private static void VerifyCannotFindTemplate(ITestOutputHelper output, string te
             // Verify we really did remove the previous templates
             var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("D"));
             Directory.CreateDirectory(tempDir);
-            try
-            {
-                var proc = ProcessEx.Run(
-                    output,
-                    tempDir,
-                    "dotnet",
-                    $"new \"{templateName}\"");
-                proc.WaitForExit(assertSuccess: false);
-                if (!proc.Error.Contains($"No templates matched the input template name: {templateName}."))
-                {
-                    throw new InvalidOperationException($"Failed to uninstall previous templates. The template '{templateName}' could still be found.");
-                }
-            }
-            finally
+
+            var proc = ProcessEx.Run(
+                output,
+                tempDir,
+                "dotnet",
+                $"new \"{templateName}\"");
+            proc.WaitForExit(assertSuccess: false);
+            if (!proc.Error.Contains($"No templates matched the input template name: {templateName}."))
             {
-                Directory.Delete(tempDir);
+                throw new InvalidOperationException($"Failed to uninstall previous templates. The template '{templateName}' could still be found.");
             }
+
+            Directory.Delete(tempDir);
         }
 
         private static string FindAncestorDirectoryContaining(string filename)