chore(toolkit): randomize tests (#33429)

### Reason for this change

Randomizing tests is good practice to ensure test cases are written in a self-contained way.

### Description of changes

Enable randomizing tests and fix mocks that were dependent on state.
Also increase minimum coverage thresholds to match current reality.

### Describe any new or updated permissions being added

n/a

### Description of how you validated changes

existing tests

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

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

Author: mrgrain

packages/@aws-cdk/toolkit/jest.config.js

@@ -1,11 +1,14 @@
 const baseConfig = require('@aws-cdk/cdk-build-tools/config/jest.config');
 module.exports = {
     ...baseConfig,
+    randomize: true,
     coverageThreshold: {
         global: {
             // this is very sad but we will get better
-            branches: 42,
-            statements: 69,
+            statements: 75,
+            branches: 55,
+            functions: 70,
+            lines: 75,
         },
     },
 };

packages/@aws-cdk/toolkit/test/actions/destroy.test.ts

@@ -7,7 +7,7 @@ const ioHost = new TestIoHost();
 const toolkit = new Toolkit({ ioHost });
 jest.spyOn(toolkit, 'rollback').mockResolvedValue();
 
-let mockDestroyStack = jest.fn().mockResolvedValue({});
+let mockDestroyStack = jest.fn();
 
 jest.mock('../../lib/api/aws-cdk', () => {
   return {
@@ -22,6 +22,7 @@ beforeEach(() => {
   ioHost.notifySpy.mockClear();
   ioHost.requestSpy.mockClear();
   jest.clearAllMocks();
+  mockDestroyStack.mockResolvedValue({});
 });
 
 describe('destroy', () => {
@@ -68,7 +69,7 @@ describe('destroy', () => {
 
   test('destroy deployment fails', async () => {
     // GIVEN
-    mockDestroyStack = jest.fn().mockRejectedValue({});
+    mockDestroyStack.mockRejectedValue({});
 
     // WHEN
     const cx = await builderFixture(toolkit, 'stack-with-role');

packages/@aws-cdk/toolkit/test/actions/rollback.test.ts

@@ -5,11 +5,7 @@ import { builderFixture, TestIoHost } from '../_helpers';
 const ioHost = new TestIoHost();
 const toolkit = new Toolkit({ ioHost });
 
-let mockRollbackStack = jest.fn().mockResolvedValue({
-  notInRollbackableState: false,
-  success: true,
-});
-
+let mockRollbackStack = jest.fn();
 jest.mock('../../lib/api/aws-cdk', () => {
   return {
     ...jest.requireActual('../../lib/api/aws-cdk'),
@@ -23,6 +19,10 @@ beforeEach(() => {
   ioHost.notifySpy.mockClear();
   ioHost.requestSpy.mockClear();
   jest.clearAllMocks();
+  mockRollbackStack.mockResolvedValue({
+    notInRollbackableState: false,
+    success: true,
+  });
 });
 
 describe('rollback', () => {