Deprecate aws-vault, aws-okta, warn about M1 chip

[Nuru]

what & why

• Remove aws-vault from image, deprecate aws-vault and aws-okta, recommend Leapp. Leapp is now our preferred solution for managing AWS credentials, and aws sso is our preferred command-line solution. aws-vault and aws-okta have issues and required a lot of specialized support that is not worth maintaining now that we have these superior solutions.
• Add Makefile.custom and Dockerfile.custom to give people a baseline for building customized version of Geodesic derived from the published version, rather than having to rebuild the entire image.
• Document that we are not yet supporting Geodesic on the Apple M1 chip. Add a warning when running Geodesic on M1. We know it doesn't work, we can't do anything about it now, our best recommendation is to stick with Intel CPUs for at least another 6 months.
• Update Google Cloud SDK 342.0.0 -> 352.0.0 (353 is current but has a breaking change, so we are waiting a while on that.)
• Update kubectx completion 0.9.3 -> 0.9.4
• Update motd (message of the day), dropping aws-vault workflow prompts and recommending Leapp. Prevent motd from displaying when launching subshells.
• Enhance assume-role to work with Leapp credentials as well as AWS config profiles. Fix fzf initial query when NAMESPACE or STAGE is not set
• Review scripts to remove/fix instances of scripts and functions clobbering existing trap settings. Scripts were clobbering both RETURN and EXIT traps, but they should now either not be overwriting existing traps or should be restoring the previous trap on RETURN or EXIT.
• Fix issue where assume-role launched a subshell with a new role, and when the shell exited, the parent shell prompt would still show the role active, even though it was not.
• Fix issue with kubectl-auto-select where it would have trouble parsing EKS Kubernetes versions and fail to select the correct corresponding version of kubectl.
• Install diffutils (GNU diff) in Alpine so that diff in Alpine behaves like diff in Debian and scripts can count on consistent options.
• Fix yaml-diff, which was expecting yq to be version 2.x and was completely broken by the substantial changes in the now current yq version 4.12.0