services: Transient inetd services inherit requirements.

That way, per-connection transient services such as 'sshd-123' inherit
dependencies of their "parent" ('sshd' in this example), which is more
consistent than not depending on anything.

* gnu/services/dict.scm (dicod-shepherd-service): Pass #:requirements to
'make-inetd-constructor'.
* gnu/services/messaging.scm (bitlbee-shepherd-service): Likewise.
* gnu/services/ssh.scm (openssh-shepherd-service): Likewise.
* gnu/services/vnc.scm (xvnc-shepherd-service): Likewise.

gnu/services/dict.scm

@@ -176,6 +176,7 @@ database {
                                 (addrinfo:addr
                                  (car (getaddrinfo #$(first interfaces)
                                                    "dict")))))
+                         #:requirements '#$requirement
                          #:user "dicod" #:group "dicod"
                          #:service-name-stem "dicod")
                         (make-forkexec-constructor

gnu/services/messaging.scm

@@ -872,6 +872,7 @@ string, you could instantiate a prosody service like this:
                                                         #$(number->string port)
                                                         (logior AI_NUMERICHOST
                                                                 AI_NUMERICSERV))))))
+                              #:requirements '#$requirement
                               #:service-name-stem "bitlbee"
                               #:user "bitlbee" #:group "bitlbee"
 

gnu/services/ssh.scm

@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014-2019, 2022 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014-2019, 2022, 2023 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2016 David Craven <david@craven.ch>
 ;;; Copyright © 2016 Julien Lepiller <julien@lepiller.eu>
 ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
@@ -607,6 +607,7 @@ of user-name/file-like tuples."
                                    (make-socket-address AF_INET6 IN6ADDR_ANY
                                                         #$port-number)))
                                  '()))
+                       #:requirements '#$requirement
                        #:max-connections #$max-connections)
                       (make-forkexec-constructor #$openssh-command
                                                  #:pid-file #$pid-file)))

gnu/services/vnc.scm

@@ -228,6 +228,7 @@ CONFIG, a <xvnc-configuration> object."
                        ,@(if ipv6-socket
                              (list (endpoint ipv6-socket))
                              '()))
+                     #:requirements '#$requirement
                      #:user "xvnc"
                      #:group "xvnc"))
                 #~(make-forkexec-constructor