Throw an error in StandardIO.resize() (#350)

Throw an error in `StandardIO.resize()`, which is unsupported.

Author: dkovba

vminitd/Sources/vminitd/StandardIO.swift

@@ -14,6 +14,7 @@
 // limitations under the License.
 //===----------------------------------------------------------------------===//
 
+import ContainerizationError
 import ContainerizationOS
 import Foundation
 import Logging
@@ -119,8 +120,9 @@ final class StandardIO: ManagedProcess.IO & Sendable {
         }
     }
 
-    // NOP
-    func resize(size: Terminal.Size) throws {}
+    func resize(size: Terminal.Size) throws {
+        throw ContainerizationError(.unsupported, message: "resize not supported")
+    }
 
     func close() throws {
         self.state.withLock {