fix(batch-alpha): cannot import FargateComputeEnvironment with fromFargateComputeEnvironmentArn (#25985)

Change the superclass of the [Import](https://github.com/aws/aws-cdk/blob/104bf32798b02f8f3c3ec5aaa05e31c35b4a38da/packages/%40aws-cdk/aws-batch-alpha/lib/managed-compute-environment.ts#L1071) class instantiated by `fromFargateComputeEnvironmentArn` from `ManagedComputeEnvironmentBase` to `Resource`.
This prevents errors due to the required `vpc` parameter of the old superclass [being passed](https://github.com/aws/aws-cdk/blob/104bf32798b02f8f3c3ec5aaa05e31c35b4a38da/packages/%40aws-cdk/aws-batch-alpha/lib/managed-compute-environment.ts#L1077-L1079) as `undefined`.

Closes #25979.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: lpizzinidev

packages/@aws-cdk/aws-batch-alpha/lib/managed-compute-environment.ts

@@ -1068,15 +1068,17 @@ export class FargateComputeEnvironment extends ManagedComputeEnvironmentBase imp
     const stack = Stack.of(scope);
     const computeEnvironmentName = stack.splitArn(fargateComputeEnvironmentArn, ArnFormat.SLASH_RESOURCE_NAME).resourceName!;
 
-    class Import extends ManagedComputeEnvironmentBase implements IFargateComputeEnvironment {
+    class Import extends Resource implements IFargateComputeEnvironment {
       public readonly computeEnvironmentArn = fargateComputeEnvironmentArn;
       public readonly computeEnvironmentName = computeEnvironmentName;
       public readonly enabled = true;
+      public readonly maxvCpus = 1;
+      public readonly connections = { } as any;
+      public readonly securityGroups = [];
+      public readonly tags: TagManager = new TagManager(TagType.MAP, 'AWS::Batch::ComputeEnvironment');
     }
 
-    return new Import(scope, id, {
-      vpc: undefined as any,
-    });
+    return new Import(scope, id);
   }
 
   public readonly computeEnvironmentName: string;

packages/@aws-cdk/aws-batch-alpha/test/managed-compute-environment.test.ts

@@ -935,4 +935,12 @@ describe('FargateComputeEnvironment', () => {
       ComputeEnvironmentName: 'maxPropsFargateCE',
     });
   });
+
+  test('can be imported from arn', () => {
+    // WHEN
+    const ce = FargateComputeEnvironment.fromFargateComputeEnvironmentArn(stack, 'import', 'arn:aws:batch:us-east-1:123456789012:compute-environment/ce-name');
+
+    // THEN
+    expect(ce.computeEnvironmentArn).toEqual('arn:aws:batch:us-east-1:123456789012:compute-environment/ce-name');
+  });
 });