Enable CI/CD

.gitlab-ci.yml

+include:
+  - project: 'Support/CI'
+    file: '/Squish.yml'
+
+deploy_to_library:
+  stage: deploy
+  only:
+    refs: [ master ]
+  tags: [ cross ]
+  script:
+    # Depending on whether the pipeline is launched by the merge request or
+    # manually, VersionNum may or may not have been updated. Switch to the
+    # tip of master to ensure consistency.
+    - git checkout origin/master
+    - SOURCETAG=$(git describe --abbrev=8 --tags --always)
+    - BRANCH=Import$(echo $SOURCETAG | sed -e 's/[-._]//g')
+    - 'curl --location --output ~/cache/common/BuildHost.zip -z ~/cache/common/BuildHost.zip "https://gitlab.riscosopen.org/Products/BuildHost/-/jobs/artifacts/master/download?job=latest_package_tree"'
+    - unzip -q ~/cache/common/BuildHost.zip
+    - '[ ! -e BuildInfo ] || cat BuildInfo'
+    - source RiscOS/Env/ROOL/BuildHost.sh
+    - git clone https://$USER:$PASSWORD@gitlab.riscosopen.org/$USER/Library.git
+    - INSTDIR=../Library/Build mk install
+    # If the installed binary has changed in any way, raise a merge request
+    - cd Library && git diff --quiet --exit-code || ( git checkout -b $BRANCH; git add .; git commit -m "Update Squish from tag $SOURCETAG"; git push -o merge_request.create -o merge_request.target=RiscOS/Library/master origin $BRANCH )