[Performance] Memoize isWsl check

[gonzaloriestra]

Memoizes the results of the isWsl check in @shopify/cli-kit to avoid redundant dynamic imports and environment checks. This improvement reduces the overhead of calling isWsl repeatedly across the codebase.

Expected Performance Impact

Reduced overhead of isWsl calls by caching the result of the dynamic import after the first call. This avoids redundant filesystem and OS checks on subsequent calls.

How to test your changes?

CI

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PR created automatically by Jules for task 11590658677194908089 started by @gonzaloriestra

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[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/public/node/system.d.ts

@@ -111,6 +111,10 @@ export declare function isCI(): boolean;
  * @returns True if the current environment is a WSL environment.
  */
 export declare function isWsl(): Promise<boolean>;
+/**
+ * Resets the memoized value for the WSL check.
+ */
+export declare function _resetIsWsl(): void;
 /**
  * Check if stdin has piped data available.
  * This distinguishes between actual piped input (e.g., )