Remove image tag for paperless-ngx chart

This update changes the image tag for the paperless-ngx Helm chart
from a specific version (2.20.1) to an empty string. This allows
the chart to use the latest available image version, which is
important for ensuring that users always receive the latest
features and security updates without needing to update the
Helm chart manually.

No breaking changes are introduced; however, users should be
aware that using an empty tag may lead to unexpected behavior
if there are breaking changes in newer image versions. Users
should ensure they test their deployments when upgrading to
monitor for any issues.

charts/paperless-ngx/values.yaml

@@ -15,7 +15,7 @@ controllers:
           # -- Image pull policy
           pullPolicy: IfNotPresent
           # -- Image tag
-          tag: 2.20.1
+          tag: ""
           # -- Environment variables [[ref]](https://docs.paperless-ngx.com/configuration/)
           # @default -- See [values.yaml](./values.yaml)
         # -- Set the resource requests / limits for the container.