Unset MAKELEVEL when running tool manager install

Overview

When mise install or asdf install is executed through a Makefile, some dependencies may fail to install because make pases along the MAKELEVEL environment variable. For example, this postgres issue (see this report in Slack (internal)).

Therefore, any time we install via a tooling manager, we should unset MAKELEVEL to not pollute any downstream Makefile.

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.