docs: remove deprecated Metadata field from gRPC naming examples

The `Metadata` field is deprecated and should no longer appear in
documentation examples. This updates etcd v3.5 and v3.6 gRPC naming guides to
reflect the current usage.

Also there is a slight update from `grpc.Dial` to `grpc.NewClient`

Signed-off-by: amosehiguese <amosehiguese@gmail.com>

Author: amosehiguese

content/en/docs/v3.5/dev-guide/grpc_naming.md

@@ -44,7 +44,7 @@ Endpoints are added to the service by creating new keys and removed from the ser
 New endpoints can be added to the service through `etcdctl`:
 
 ```sh
-ETCDCTL_API=3 etcdctl put foo/bar/my-service/1.2.3.4 '{"Addr":"1.2.3.4","Metadata":"..."}'
+ETCDCTL_API=3 etcdctl put foo/bar/my-service/1.2.3.4 '{"Addr":"1.2.3.4"}'
 ```
 
 The etcd client's `endpoints.Manager` method can also register new endpoints with a key matching the `Addr`:
@@ -59,8 +59,8 @@ To enable round-robin load balancing when dialing service with multiple endpoint
 
  ```go
 
- 	conn, gerr := grpc.Dial("etcd:///foo", grpc.WithResolvers(etcdResolver),
- 		grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"round_robin"}`))
+conn, gerr := grpc.NewClient("etcd:///foo", grpc.WithResolvers(etcdResolver),
+grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"round_robin"}`))
  ```
 
 ### Deleting an endpoint
@@ -84,7 +84,7 @@ Registering an endpoint with a lease ensures that if the host can't maintain a k
 
 ```sh
 lease=`ETCDCTL_API=3 etcdctl lease grant 5 | cut -f2 -d' '`
-ETCDCTL_API=3 etcdctl put --lease=$lease my-service/1.2.3.4 '{"Addr":"1.2.3.4","Metadata":"..."}'
+ETCDCTL_API=3 etcdctl put --lease=$lease my-service/1.2.3.4 '{"Addr":"1.2.3.4"}'
 ETCDCTL_API=3 etcdctl lease keep-alive $lease
 ```
 In the golang:

content/en/docs/v3.6/dev-guide/grpc_naming.md

@@ -44,7 +44,7 @@ Endpoints are added to the service by creating new keys and removed from the ser
 New endpoints can be added to the service through `etcdctl`:
 
 ```sh
-ETCDCTL_API=3 etcdctl put foo/bar/my-service/1.2.3.4 '{"Addr":"1.2.3.4","Metadata":"..."}'
+ETCDCTL_API=3 etcdctl put foo/bar/my-service/1.2.3.4 '{"Addr":"1.2.3.4"}'
 ```
 
 The etcd client's `endpoints.Manager` method can also register new endpoints with a key matching the `Addr`:
@@ -59,8 +59,8 @@ To enable round-robin load balancing when dialing service with multiple endpoint
 
  ```go
 
- 	conn, gerr := grpc.Dial("etcd:///foo", grpc.WithResolvers(etcdResolver),
- 		grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"round_robin"}`))
+conn, gerr := grpc.NewClient("etcd:///foo", grpc.WithResolvers(etcdResolver),
+grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"round_robin"}`))
  ```
 
 ### Deleting an endpoint
@@ -84,7 +84,7 @@ Registering an endpoint with a lease ensures that if the host can't maintain a k
 
 ```sh
 lease=`ETCDCTL_API=3 etcdctl lease grant 5 | cut -f2 -d' '`
-ETCDCTL_API=3 etcdctl put --lease=$lease my-service/1.2.3.4 '{"Addr":"1.2.3.4","Metadata":"..."}'
+ETCDCTL_API=3 etcdctl put --lease=$lease my-service/1.2.3.4 '{"Addr":"1.2.3.4"}'
 ETCDCTL_API=3 etcdctl lease keep-alive $lease
 ```
 In the golang: