Revert "file-systems: %base-file-systems: Add tmpfs /run."

This reverts commit e88018be70.  Since this
change breaks current dbus-service-type, it would be better to wait
https://issues.guix.gnu.org/73494 finished.

doc/guix.texi

@@ -18228,11 +18228,6 @@ The daemon itself is still able to write to the store: it remounts it
 read-write in its own ``name space.''
 @end defvar
 
-@defvar %runtime-variable-data
-This file system is mounted as @file{/run} and contains system
-information data describing the system since it was booted.
-@end defvar
-
 @defvar %binary-format-file-system
 The @code{binfmt_misc} file system, which allows handling of arbitrary
 executable file types to be delegated to user space.  This requires the

gnu/services.scm

@@ -632,7 +632,7 @@ information is missing, return the empty list (for channels) and possibly
     #~(begin
         (use-modules (guix build utils))
 
-        ;; Clean out /tmp and /var/run.
+        ;; Clean out /tmp, /var/run, and /run.
         ;;
         ;; XXX This needs to happen before service activations, so it
         ;; has to be here, but this also implicitly assumes that /tmp
@@ -663,12 +663,15 @@ information is missing, return the empty list (for channels) and possibly
            (setlocale LC_CTYPE "en_US.utf8")
            (delete-file-recursively "/tmp")
            (delete-file-recursively "/var/run")
+           (delete-file-recursively "/run")
 
            ;; Note: The second argument to 'mkdir' is and'ed with umask,
            ;; hence the 'chmod' calls.
            (mkdir "/tmp" #o1777)
            (chmod "/tmp" #o1777)
            (mkdir "/var/run" #o755)
+           (chmod "/var/run" #o755)
+           (mkdir "/run" #o755)
            (chmod "/var/run" #o755))))))
 
 (define cleanup-service-type

gnu/system/file-systems.scm

@@ -82,7 +82,6 @@
             %pseudo-terminal-file-system
             %tty-gid
             %immutable-store
-            %runtime-variable-data
             %control-groups
             %elogind-file-systems
 
@@ -449,17 +448,6 @@ TARGET in the other system."
     (check? #f)
     (flags '(read-only bind-mount no-atime))))
 
-(define %runtime-variable-data
-  (file-system
-    (type "tmpfs")
-    (mount-point "/run")
-    (device "tmpfs")
-    (flags '(no-suid no-dev strict-atime))
-    (options "mode=0755,nr_inodes=800k,size=20%")
-    (needed-for-boot? #t)
-    (check? #f)
-    (create-mount-point? #t)))
-
 (define %control-groups
   ;; The cgroup2 file system.
   (list (file-system
@@ -509,8 +497,7 @@ TARGET in the other system."
         %debug-file-system
         %shared-memory-file-system
         %efivars-file-system
-        %immutable-store
-        %runtime-variable-data))
+        %immutable-store))
 
 (define %base-live-file-systems
   ;; This is the bare minimum to use live file-systems.