NS records added in Google Cloud DNS must have a trailing dot. Otherwise the API throws the following error:
```
time="2024-11-04T10:34:20Z" level=error msg="googleapi: Error 400: Invalid value for 'entity.change.additions[cloud.k8gb.io.][NS].rrdata[0]': 'gslb-ns-eu-cloud.k8gb.io', invalid"
```
This is similar to CNAME, MX and SRV records.
---
This change was tested with the a DNSEndpoint CRD containing the following endpoints:
```
endpoints:
- dnsName: cloud.k8gb.io
recordTTL: 5
recordType: NS
targets:
- gslb-ns-eu-cloud.k8gb.io
- gslb-ns-us-cloud.k8gb.io
- dnsName: gslb-ns-eu-cloud.k8gb.io
```
And the record was successfully created
```
gcloud dns record-sets list --zone="k8gb" --type=NS --name "cloud.k8gb.io."
NAME TYPE TTL DATA
cloud.k8gb.io. NS 5 gslb-ns-eu-cloud.k8gb.io.,gslb-ns-us-cloud.k8gb.io.
```
Signed-off-by: Andre Aguas <andre.aguas@protonmail.com>