fix: remove incorrect digest pinning from image reference

Reviewed-on: #254

.gitlab-ci.yml

@@ -1,27 +0,0 @@
-include:
-- template: 'Workflows/MergeRequest-Pipelines.gitlab-ci.yml'
-- project: unboundsoftware/ci-templates
-  file: Defaults.gitlab-ci.yml
-
-stages:
-  - build
-  - deploy
-
-image: buildtool/build-tools:${BUILDTOOLS_VERSION}
-
-build:
-  stage: build
-  script:
-    - build
-    - push
-
-deploy:
-  stage: deploy
-  when: on_success
-  script:
-    - echo Deploying
-    - deploy prod
-  environment:
-    name: prod
-  only:
-    - master