refactor(pipelines): simplify CLI dependency version

packages/aws-cdk-lib/package.json

@@ -525,7 +525,6 @@
     "./region-info": "./region-info/index.js",
     "./triggers": "./triggers/index.js"
   },
-  "preferredCdkCliVersion": "2",
   "publishConfig": {
     "tag": "latest"
   },

packages/aws-cdk-lib/pipelines/lib/codepipeline/codepipeline.ts

@@ -21,7 +21,6 @@ import { GraphNodeCollection, isGraph, AGraphNode, PipelineGraph } from '../help
 import { PipelineBase } from '../main';
 import { AssetSingletonRole } from '../private/asset-singleton-role';
 import { CachedFnSub } from '../private/cached-fnsub';
-import { preferredCliVersion } from '../private/cli-version';
 import { appOf, assemblyBuilderOf, embeddedAsmPath, obtainScope } from '../private/construct-internals';
 import { CDKP_DEFAULT_CODEBUILD_IMAGE } from '../private/default-codebuild-image';
 import { toPosixPath } from '../private/fs';
@@ -425,7 +424,7 @@ export class CodePipeline extends PipelineBase {
     this.selfMutationEnabled = props.selfMutation ?? true;
     this.dockerCredentials = props.dockerCredentials ?? [];
     this.singlePublisherPerAssetType = !(props.publishAssetsInParallel ?? true);
-    this.cliVersion = props.cliVersion ?? preferredCliVersion();
+    this.cliVersion = props.cliVersion ?? '2';
     this.cdkAssetsCliVersion = props.cdkAssetsCliVersion ?? 'latest';
     this.useChangeSets = props.useChangeSets ?? true;
     this.stackOutputs = new StackOutputsMap(this);

packages/aws-cdk-lib/pipelines/test/codepipeline/codepipeline.test.ts

@@ -277,6 +277,32 @@ test('CodeBuild asset role has the right Principal with the feature enabled', ()
   );
 });
 
+test.each([
+  [undefined, '2'],
+  ['9.9.9', '9.9.9'],
+])('When I request CLI version version %p I get %p', (requested, expected) => {
+  const pipelineStack = new cdk.Stack(app, 'PipelineStack', { env: PIPELINE_ENV });
+  const pipe = new ModernTestGitHubNpmPipeline(pipelineStack, 'Cdk', {
+    cliVersion: requested,
+  });
+
+  pipe.addStage(new FileAssetApp(pipelineStack, 'App', {}));
+
+  Template.fromStack(pipelineStack).hasResourceProperties('AWS::CodeBuild::Project', {
+    Source: {
+      BuildSpec: Match.serializedJson(Match.objectLike({
+        phases: {
+          install: {
+            commands: [
+              `npm install -g aws-cdk@${expected}`,
+            ],
+          },
+        },
+      })),
+    },
+  });
+});
+
 test('CodeBuild asset role has the right Principal with the feature disabled', () => {
   const stack = new cdk.Stack();
   stack.node.setContext(cxapi.PIPELINE_REDUCE_ASSET_ROLE_TRUST_SCOPE, false);