GitLab: Remove tags for sandbox_noinst tests

Commit 712cc962 ("GitLab: Remove "tags" stanzas") removed the 'all'
tag from all the jobs. The sandbox_noinst_test.py test was added in
between the author date and commit date (commit 6c914e42
("azure/gitlab: Add tests for sandbox_noinst")) which is probably why it
still contains the tags. This commit fixes that so all jobs now don't
require tags on the GitLab runners.

Signed-off-by: Harm Berntsen <harm.berntsen@nedap.com>
CC: Simon Glass <sjg@chromium.org>
Acked-by: Pratyush Yadav <p.yadav@ti.com>