cmd/k8s-operator: Move login server value to top-level (#16470)

This commit modifies the operator helm chart values to bring the newly
added `loginServer` field to the top level. We felt as though it was a bit
confusing to be at the `operatorConfig` level as this value modifies the
behaviour or the operator, api server & all resources that the operator
manages.

Updates https://github.com/tailscale/corp/issues/29847

Signed-off-by: David Bond <davidsbond93@gmail.com>

cmd/k8s-operator/deploy/chart/templates/deployment.yaml

@@ -69,7 +69,7 @@ spec:
                 fieldRef:
                   fieldPath: metadata.namespace
             - name: OPERATOR_LOGIN_SERVER
-              value: {{ .Values.operatorConfig.loginServer }}
+              value: {{ .Values.loginServer }}
             - name: CLIENT_ID_FILE
               value: /oauth/client_id
             - name: CLIENT_SECRET_FILE