feat: create temporary directories

[david-christiansen]

This PR adds a primitive for creating temporary directories, akin to the existing functionality for creating temporary files.

[leanprover-community-bot]

Mathlib CI status (docs):

• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase b89446419102c77c5292ce4138f8bbd4d96da46f --onto 7fbe8e3b36faabc9cfcc45e65a4b7ef042c0b068. (2024-11-21 09:02:49)
• ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase b89446419102c77c5292ce4138f8bbd4d96da46f --onto 72e952eadc6a171310f1d8e9d6e78acf98421494. (2024-11-22 12:27:28)