istioctl doesn't include charts

[nightkr]

Describe the bug

Our build of istioctl doesn't include charts, which breaks the istioctl install mechanism.

To Reproduce
Steps to reproduce the behavior:

1. Install Docker
2. Create K8s cluster: nix run nixpkgs.kind -c kind create cluster
3. Try to install Istio into the cluster: nix run nixpkgs.istioctl -c istioctl install
4. Install fails with:

Error: failed to apply manifests: compiled in charts not found in this development build, use --charts with local charts instead or run make gen-charts

Expected behavior
Istio is installed into the cluster.

Screenshots
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Additional context
Add any other context about the problem here.

Notify maintainers
@veehaitch

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.7.10-arch1-1, Arch Linux, noversion
• multi-user?: no
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(teo): "nixpkgs-20.09pre236138.970b2b853d4"
• nixpkgs: /home/teo/.nix-defexpr/channels/nixpkgs

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
- istioctl
# a list of nixos modules affected by the problem
module: