ci: pin Tuist with mise

[BugenZhao]

Summary

• add a committed .tool-versions file for Tuist 4.131.1
• let GitHub Actions read the pinned Tuist version from mise config
• keep fastlane release checkout clean before TestFlight upload

Checks

• ruby YAML parse for iOS workflow files

[Copilot]

Pull request overview

This PR centralizes the Tuist version pin for the iOS build/release workflows by committing a .tool-versions file and letting jdx/mise-action read the pinned version from repository configuration, instead of hardcoding it in each workflow.

Changes:

• Add .tool-versions to pin tuist 4.131.1 in-repo.
• Remove the per-workflow tool_versions: tuist 4.131.1 override from the iOS debug and release GitHub Actions workflows so they rely on the repo pin.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
.tool-versions	Adds a committed Tuist version pin (4.131.1) for mise/asdf-style tool resolution.
.github/workflows/release.yaml	Removes hardcoded Tuist version input so mise-action uses the repo’s .tool-versions.
.github/workflows/ios_debug.yaml	Same as release workflow: relies on .tool-versions instead of inlining the Tuist version.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.