Set mise as default tool version manager for new installs

Overview

• Currently, the one line install script allows the user to select either mise or asdf as the tool version manager.
• The default selection is asdf.
• Starting March 1st, 2025, mise will replace asdf as the supported tool version manager for GDK.
• The default selection should be changed to mise for new installs, where possible and can be done before the changeover date.

Impacted categories

The following categories relate to this issue:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Proposal

Set DEFAULT_TOOL_VERSION_MANAGER to mise and update prompts accordingly.