[shellenv] filter out DEVBOX_LATEST_VERSION env var

[savil]

Summary

The Devbox launcher invokes the Devbox binary with DEVBOX_LATEST_VERSION env-var
being set. The Devbox binary uses this env-var to determine if a new version is
available, and if it needs to alert the user to update.

This env-var was never intended to be "exported" to the rest of the environment.
However, devbox shellenv was doing so.

This becomes problematic if a user does eval $(devbox global shellenv) in
their shellrc file, and has done devbox global add coreutils. Then, doing ls
or cat <file>, or using any of the coreutils programs seems to trigger
an avalanche of "new Devbox available" notices.

Fix:
this PR filters out DEVBOX_LATEST_VERSION from the environment that shellenv
exports.

How was it tested?

> export DEVBOX_LATEST_VERSION=0.5.12

# verify it was being exported
> devbox shellenv | grep "DEVBOX_LATEST"
DEVBOX_LATEST_VERSION=0.5.12

> devbox run build

# no longer present
> devbox shellenv | grep "DEVBOX_LATEST"

[savil]

Current dependencies on/for this PR:

• main
  • PR [shellenv] filter out DEVBOX_LATEST_VERSION env var #1331 👈

This comment was auto-generated by Graphite.

[mikeland73]

Seems safe enough