[0.68] fix(cli): fix cache not being used when there are no dependenc…

…ies (#9548)

This PR backports #9522 to 0.68.

- Bug fix (non-breaking change which fixes an issue)
This addresses a perf regression in autolinking when there are no dependencies to link.

Resolves #9518

Instead of checking whether the dependencies cache is empty, check whether it was instantiated.

| Before | After |
| -: | -: |
| 22488ms | 3561ms |

Co-authored-by: Tommy Nguyen <4123478+tido64@users.noreply.github.com>

change/@react-native-windows-cli-401a1aee-fc62-4128-b881-42b970e6102e.json

@@ -0,0 +1,7 @@
+{
+ "type": "prerelease",
+ "comment": "[0.68] Fix cache not being used when there are no dependencies",
+ "packageName": "@react-native-windows/cli",
+ "email": "4123478+tido64@users.noreply.github.com",
+ "dependentChangeType": "patch"
+}

packages/@react-native-windows/cli/src/runWindows/utils/autolink.ts

@@ -398,13 +398,13 @@ export class AutolinkWindows {
  }
 
  /** Cache of dependencies */
- private readonly windowsDependencies: Record<
- string,
- WindowsDependencyConfig
- > = {};
+ private windowsDependencies:
+ | Record<string, WindowsDependencyConfig>
+ | undefined;
 
  private getWindowsDependencies() {
- if (Object.keys(this.windowsDependencies).length === 0) {
+ if (!this.windowsDependencies) {
+ this.windowsDependencies = {};
  for (const dependencyName of Object.keys(this.dependenciesConfig)) {
  const windowsDependency: WindowsDependencyConfig | undefined =
  this.dependenciesConfig[dependencyName].platforms.windows;