fix(core): cache getting the package manager to the module scope (#25992

)

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## Current Behavior
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This function is called many times and they all `exec` a command

## Expected Behavior
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This function is called once and the result is cached.

## Related Issue(s)
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Fixes #

(cherry picked from commit 12c6a73)

packages/nx/src/utils/package-json.ts

@@ -136,11 +136,13 @@ export function buildTargetFromScript(
   };
 }
 
+let packageManagerCommand: PackageManagerCommands | undefined;
+
 export function readTargetsFromPackageJson(packageJson: PackageJson) {
   const { scripts, nx, private: isPrivate } = packageJson ?? {};
   const res: Record<string, TargetConfiguration> = {};
   const includedScripts = nx?.includedScripts || Object.keys(scripts ?? {});
-  const packageManagerCommand = getPackageManagerCommand();
+  packageManagerCommand ??= getPackageManagerCommand();
   for (const script of includedScripts) {
     res[script] = buildTargetFromScript(script, scripts, packageManagerCommand);
   }