Fix some binaries to print the versions (#15306)

Signed-off-by: Manan Gupta <manan@planetscale.com>

go/cmd/mysqlctld/cli/mysqlctld.go

@@ -67,6 +67,7 @@ var (
 	--mysql_port=17100 \
 	--socket_file=/path/to/socket_file`,
 		Args:    cobra.NoArgs,
+		Version: servenv.AppVersion.String(),
 		PreRunE: servenv.CobraPreRunE,
 		RunE:    run,
 	}

go/cmd/topo2topo/cli/topo2topo.go

@@ -52,6 +52,7 @@ var (
 It can also be used to compare data between two topologies.`,
 		Args:    cobra.NoArgs,
 		PreRunE: servenv.CobraPreRunE,
+		Version: servenv.AppVersion.String(),
 		RunE:    run,
 	}
 )

go/cmd/vtexplain/cli/vtexplain.go

@@ -84,6 +84,7 @@ If no keyspace name is present, VTExplain will return the following error:
 			"```\nvtexplain -- -shards 128 --vschema-file vschema.json --schema-file schema.sql --replication-mode \"ROW\" --output-mode text --sql \"INSERT INTO users (user_id, name) VALUES(1, 'john')\"\n```\n",
 		Args:    cobra.NoArgs,
 		PreRunE: servenv.CobraPreRunE,
+		Version: servenv.AppVersion.String(),
 		RunE:    run,
 	}
 )

go/cmd/vttestserver/cli/main.go

@@ -104,6 +104,7 @@ func New() (cmd *cobra.Command) {
 		Short:   "vttestserver allows users to spawn a self-contained Vitess server for local testing/CI.",
 		Args:    cobra.NoArgs,
 		PreRunE: servenv.CobraPreRunE,
+		Version: servenv.AppVersion.String(),
 		RunE:    run,
 	}
 

go/cmd/zkctld/cli/zkctld.go

@@ -41,6 +41,7 @@ var (
 		Use:               "zkctld",
 		Short:             "zkctld is a daemon that starts or initializes ZooKeeper with Vitess-specific configuration. It will stay running as long as the underlying ZooKeeper server, and will pass along SIGTERM.",
 		Args:              cobra.NoArgs,
+		Version:           servenv.AppVersion.String(),
 		PersistentPreRunE: servenv.CobraPreRunE,
 		PostRun: func(cmd *cobra.Command, args []string) {
 			logutil.Flush()

go/flags/endtoend/zkctld.txt

@@ -4,4 +4,5 @@ Usage:
   zkctld [flags]
 
 Flags:
-  -h, --help   help for zkctld
+  -h, --help      help for zkctld
+  -v, --version   version for zkctld