bootstrap: use runners with 'docker' and 'gce' tags for the image creation

As we currently have the 'shared' tag on our private runners, they
maybe selected for image creation, but it fails there.

A lot of shared runners provide 'docker' and 'gce' and they are able to
generate the images.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

.gitlab-ci.yml

@@ -22,7 +22,7 @@ variables:
   # Set this to the contents of bootstrap/sha1sum.txt
   # which is generated by bootstrap/template.py --render
   #
-  SAMBA_CI_CONTAINER_TAG: 187702e2a9c65f874aa13e5eb1c8b68703e72299
+  SAMBA_CI_CONTAINER_TAG: 8a3bbedea9514a337ed39d8c4e88abb17c43f975
   #
   # We use the ubuntu1804 image as default as
   # it matches what we have on sn-devel-184.

bootstrap/.gitlab-ci.yml

@@ -6,7 +6,7 @@ services:
   stage: images
   tags:
     - docker
-    - shared
+    - gce
   variables:
     SAMBA_CI_IS_BROKEN_IMAGE: "no"
   before_script:

bootstrap/sha1sum.txt

@@ -1 +1 @@
-187702e2a9c65f874aa13e5eb1c8b68703e72299
+8a3bbedea9514a337ed39d8c4e88abb17c43f975