feat: auto detect package manager

[nstringham]

fixes #455 by auto detecting if the user's project uses npm, yarn, or pnpm.

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[gemini-code-assist]

Code Review

This pull request introduces dynamic package manager detection to determine whether to use npx, yarn dlx, or pnpm dlx when executing firebase-tools, based on the presence of project lock files. Feedback suggests addressing compatibility issues with Yarn 1.x, which does not support the dlx command, and optimizing performance by caching the detected package manager to avoid repeated synchronous file system checks.