setup_sysroot: Fix build using command:, not script:

Oops. Commit 54240d3b broke the build as I botched the directive to
use, leaving `script:` even if `command:` was now the right one as
`install` is a system command and not a local script.

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

apertis-ospack-basesdk.yaml

@@ -714,7 +714,7 @@ actions:
   - action: run
     description: "Setting up sysroot storage"
     chroot: true
-    script: install -d -m 0755 -o user -g user /home/sysroot
+    command: install -d -m 0755 -o user -g user /home/sysroot
   {{ end }}
 
   - action: run

apertis-ospack-sdk.yaml

@@ -719,7 +719,7 @@ actions:
   - action: run
     description: "Setting up sysroot storage"
     chroot: true
-    script: install -d -m 0755 -o user -g user /home/sysroot
+    command: install -d -m 0755 -o user -g user /home/sysroot
   {{ end }}
 
   - action: run