gnu: guix-build-coordinator: Update to 0-94.c4c4f5a.

This also switches to use guile-next, which includes important fixes to
invalid unicode handling with suspendable ports, which is necessary for the
agent.

* gnu/packages/package-management.scm (guix-build-coordinator): Update to
0-94.c4c4f5a.
* gnu/services/guix.scm: Use guile-next for the coordinator service.

Change-Id: I853539a612fd0b41a6c63069c6291b3f42e5cdee

gnu/packages/package-management.scm

@@ -1510,8 +1510,8 @@ environments.")
                   "0k9zkdyyzir3fvlbcfcqy17k28b51i20rpbjwlx2i1mwd2pw9cxc")))))))
 
 (define-public guix-build-coordinator
-  (let ((commit "e4af682452580298b34681d37818a16771a17c66")
-        (revision "93"))
+  (let ((commit "c4c4f5ae043562276b11c2bd1174d3e24bedcd6e")
+        (revision "94"))
     (package
       (name "guix-build-coordinator")
       (version (git-version "0" revision commit))
@@ -1522,7 +1522,7 @@ environments.")
                       (commit commit)))
                 (sha256
                  (base32
-                  "1i8x9nfpvg832lxwbpjl1kadldpkcnjlxdxl4c5jqx2hz680ylf3"))
+                  "1212iskqlxgpyib1p7p1204a0kxmpxqyjv6q0pkypx6jg7f4lmjx"))
                 (file-name (string-append name "-" version "-checkout"))))
       (build-system gnu-build-system)
       (arguments
@@ -1606,9 +1606,9 @@ environments.")
              guile-prometheus
              guile-fibers
              guile-lib
-             (first (assoc-ref (package-native-inputs guix) "guile"))))
+             guile-next))
       (inputs
-       (list (first (assoc-ref (package-native-inputs guix) "guile"))
+       (list guile-next
              sqlite
              bash-minimal
              (libc-utf8-locales-for-target)
@@ -1648,9 +1648,9 @@ outputs of those builds.")
            guix
            guile-prometheus
            guile-lib
-           (first (assoc-ref (package-native-inputs guix) "guile"))))
+           guile-next))
     (inputs
-     (list (first (assoc-ref (package-native-inputs guix) "guile"))
+     (list guile-next
            bash-minimal
            (libc-utf8-locales-for-target)))
     (propagated-inputs

gnu/services/guix.scm

@@ -171,7 +171,7 @@
   (parallel-hooks                  guix-build-coordinator-configuration-parallel-hooks
                                    (default '()))
   (guile                           guix-build-coordinator-configuration-guile
-                                   (default guile-3.0-latest))
+                                   (default guile-next))
   (extra-environment-variables
    guix-build-coordinator-configuration-extra-environment-variables
    (default '())))
@@ -246,7 +246,7 @@
                                                    client-communication-uri-string
                                                    (hooks '())
                                                    (parallel-hooks '())
-                                                   (guile guile-3.0))
+                                                   (guile guile-next))
   (program-file
    "start-guix-build-coordinator"
    (with-extensions (cons guix-build-coordinator-package