gitlab: include new aarch32 job in custom-runners

Without linking it in it won't be presented on the UI. Also while
doing that fix the misnamed job from 20.40 to 20.04.

Fixes: cc44a16002 ("gitlab: add a new aarch32 custom runner definition")
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220315121954.2283887-1-alex.bennee@linaro.org>

.gitlab-ci.d/custom-runners.yml

@@ -16,4 +16,5 @@ variables:
 include:
   - local: '/.gitlab-ci.d/custom-runners/ubuntu-20.04-s390x.yml'
   - local: '/.gitlab-ci.d/custom-runners/ubuntu-20.04-aarch64.yml'
+  - local: '/.gitlab-ci.d/custom-runners/ubuntu-20.04-aarch32.yml'
   - local: '/.gitlab-ci.d/custom-runners/centos-stream-8-x86_64.yml'