Downgrade kubectl

After foo-baring apt upgrade npm, everthing was hosed:

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add –
OK

sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"

sudo apt-add-repository “deb http://apt.kubernetes.io/ kubernetes-xenial main” frank@kubemaster
Hit:1 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:3 https://aquasecurity.github.io/trivy-repo/deb focal InRelease
Hit:4 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:5 https://apt.releases.hashicorp.com focal InRelease
Get:6 http://archive.ubuntu.com/ubuntu focal-updates InRelease [128 kB]
Hit:7 https://packages.microsoft.com/ubuntu/20.04/prod focal InRelease
Ign:2 https://packages.cloud.google.com/apt kubernetes-xenial InRelease
Hit:8 http://archive.ubuntu.com/ubuntu focal-backports InRelease
Err:9 https://packages.cloud.google.com/apt kubernetes-xenial Release
404 Not Found [IP: 74.125.138.100 443]
Reading package lists… Done
E: The repository ‘http://apt.kubernetes.io kubernetes-xenial Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | \
  sudo tee /usr/share/keyrings/kubernetes-archive-keyring.gpg > /dev/null

sudo apt-add-repository "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main"