Docker: Pass environment variable to aiida-prepare script (#6169)

Set `with-contenv` such that environment variables are forwarded. Without
this, settings like the work dir of `localhost` will be set incorrectly and will cause
calculations to fail.

Cherry-pick: 6123f52

.docker/aiida-core-base/s6-assets/s6-rc.d/aiida-prepare/up

@@ -1,4 +1,6 @@
 #!/command/execlineb -S0
 
+with-contenv
+
 foreground { s6-echo "Calling /etc/init/aiida-prepare" }
 /etc/init/aiida-prepare.sh

.docker/tests/test_aiida.py

@@ -30,3 +30,11 @@ def test_verdi_status(aiida_exec, container_user, timeout):
 
     # check that we have suppressed the warnings
     assert 'Warning' not in output
+
+
+def test_computer_setup_success(aiida_exec, container_user, timeout):
+    time.sleep(timeout)
+    output = aiida_exec('verdi computer test localhost', user=container_user).decode().strip()
+
+    assert 'Success' in output
+    assert 'Failed' not in output