fix: targetGroup errors appear in containerDefinition diff (#1258)

The [container definition](https://www.pulumi.com/registry/packages/aws/api-docs/ecs/taskdefinition/#containerdefinitions_nodejs)
property of a Task Definition is a JSON string. We do not provide types
for the container definition which means it is possible to include
things in that JSON string that shouldn't be there. In the case of this
bug, we are including an additional `targetGroup` object in the
container definition string.

To fix this, I am removing the `targetGroup` field. 

fix #1248

awsx/ecs/container.test.ts

@@ -57,7 +57,6 @@ describe("port mappings", () => {
       hostPort: 2,
       name: "test-mapping-1-2",
       protocol: "tcp",
-      targetGroup,
     });
   });
 });

awsx/ecs/containers.ts

@@ -101,7 +101,9 @@ export function getMappingInputs(
   tgPort: number | undefined,
 ): schema.TaskDefinitionPortMappingInputs {
   return {
-    ...mappingInput,
+    name: mappingInput.name,
+    containerPortRange: mappingInput.containerPortRange,
+    appProtocol: mappingInput.appProtocol,
     containerPort: mappingInput.containerPort ?? mappingInput.hostPort ?? tgPort,
     hostPort: mappingInput.hostPort ?? tgPort ?? mappingInput.containerPort,
     protocol: mappingInput.protocol,