The errors in `update-codegen.sh` are silenced

https://github.com/knative-extensions/knobots/blob/f15f57f3ccfa478ef136d536b108b1db08dd47c2/actions/update-deps/entrypoint.sh#L65

This line is probably buggy. In shell, if the whole line will be evaluated as conditional, and conditionals doesn't fail the script.

It most likely should be:

```sh
if [[ ! -f hack/update-codegen.sh ]]; then
./hack/update-codegen.sh
fi
```

/kind bug

Start at actions/update-deps/entrypoint.sh around line 65 and inspect how it invokes hack/update-codegen.sh. Verify the shell condition does not suppress failures, then confirm the action reports a failure when the update script fails.

Written by the indexing model from the issue text.