fix(drift): helm hook check

[maxime1907]

Fixes these issues:

• Hook error

  $ helm drift run my-release -n default --from-release --log-level debug --kube-context kind-kind
  {"level":"debug","msg":"all manifests rendered to disk was cleaned","time":"2023-09-26T12:51:39+02:00"}
  {"level":"debug","msg":"got all required values to identify drifts from chart/release 'my-release' proceeding furter to fetch the same","time":"2023-09-26T12:51:39+02:00"}
  {"level":"debug","msg":"from-release is selected, hence fetching manifests for 'my-release' from helm release","time":"2023-09-26T12:51:39+02:00"}
  {"level":"debug","msg":"fetching chart manifest for release 'my-release' from kube cluster","time":"2023-09-26T12:51:39+02:00"}
  {"level":"debug","msg":"chart manifest for release 'my-release' was successfully retrieved from kube cluster","time":"2023-09-26T12:51:39+02:00"}
  {"level":"debug","msg":"splitting helm manifests with regex pattern: '---\\n# Source:\\s.*.'","time":"2023-09-26T12:51:39+02:00"}
  2023/09/26 12:51:39 from_template.go:141: failed to get key 'failed to identify the manifest as chart hook' from the manifest ''
  Error: plugin "drift" exited with error

[maxime1907]

cc @nikhilsbhat