"This CLI deprecated. Please reinstall from https://cli.heroku.com"

We had a simple ruby app that used the Ruby buildpack, this buildpack, and Heroku scheduler to do `heroku pg:backups capture #{database} -a #{app}` every hour. About two weeks ago this started failing. When I `heroku run bash -a ` into the app and try to manually run the commands, I get first the error:

```
~ $ heroku pg:backups -a karat
▸ heroku-cli: This CLI is deprecated. Please reinstall from https://cli.heroku.com
▸ Invalid credentials provided.
▸ API key is currently set by the HEROKU_API_KEY environment variable.
▸ Ensure this is set to a correct value or unset it to use the netrc file.
~ $ heroku --version
▸ heroku-cli: This CLI is deprecated. Please reinstall from https://cli.heroku.com
```

Is this buildpack up to date? Thanks.