[Performance] Memoize isTerminalInteractive

[gonzaloriestra]

Memoize the isTerminalInteractive function in @shopify/cli-kit to avoid redundant environment variable and stream property lookups. Added a reset utility for test isolation.

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PR created automatically by Jules for task 151826568706229761 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/context/local.d.ts

@@ -5,6 +5,10 @@ import { Metadata } from '../../../private/node/context/utilities.js';
  * @returns True if the terminal is interactive.
  */
 export declare function isTerminalInteractive(): boolean;
+/**
+ * Resets the memoized value for the terminal interactive check.
+ */
+export declare function _resetIsTerminalInteractiveCache(): void;
 /**
  * Returns the path to the user's home directory.
  *