remote: Remove '--system' argument.

* gnu/services.scm (activation-script): Return a <program-file> rather
than a <scheme-file>.
* gnu/deploy.scm (guix-deploy): Remove handling for '--system'.
(show-help): Remove documentation for '--system'.
(%default-options): Remove default setting for 'system'.

guix/scripts/deploy.scm

@@ -43,8 +43,6 @@
 (define (show-help)
   (display (G_ "Usage: guix deploy [OPTION] FILE...
 Perform the deployment specified by FILE.\n"))
-  (display (G_ "
-  -s, --system=SYSTEM    attempt to build for SYSTEM--e.g., \"i686-linux\""))
   (show-build-options-help)
   (newline)
   (display (G_ "
@@ -66,8 +64,7 @@ Perform the deployment specified by FILE.\n"))
          %standard-build-options))
 
 (define %default-options
-  `((system . ,(%current-system))
-    (substitutes? . #t)
+  `((substitutes? . #t)
     (build-hook? . #t)
     (graft? . #t)
     (debug . 0)
@@ -92,7 +89,6 @@ Perform the deployment specified by FILE.\n"))
       (set-build-options-from-command-line store opts)
       (for-each (lambda (machine)
                   (info (G_ "deploying to ~a...") (machine-display-name machine))
-                  (parameterize ((%current-system (assq-ref opts 'system))
-                                 (%graft? (assq-ref opts 'graft?)))
+                  (parameterize ((%graft? (assq-ref opts 'graft?)))
                     (run-with-store store (deploy-machine machine))))
                 machines))))