Draft: fix: append new *protected suffix to cache keys as Gitlab does

Context: On 2022-04-28 Gitlab introduced a regression by automatically adding a suffix to caches based on whether the branch was protected. The following code adds that suffix as well to query the cache.

See:

• gitlab-org/gitlab#360910
• https://gitlab.com/gitlab-org/gitlab/-/merge_requests/86107/diffs#fa6cef4c2c6f398d87d46ae6584eaec407365c19_450_454

gitlab-ci/stages/jobgraph_schedules/stage.yml

----
-loader: jobgraph.loader.transform:loader
-
-transforms:
-- jobgraph.transforms.job:transforms
-
-
-job_defaults:
-    before_script:
-    - cd "${TF_ROOT}"
-    image: {in_tree: jobgraph}
-    optimization:
-        skip_unless_changed:
-        - gitlab-ci/schedules.yml
-    # We need to get access to $JOBGRAPH_BOT_GITLAB_TOKEN even for a `terraform plan`
-    run_on_git_branches:
-    - main
-    runner_alias: misc
-    variables:
-        TF_ADDRESS: ${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/terraform/state/jobgraph
-        TF_ROOT: ${CI_PROJECT_DIR}/terraform
-
-jobs:
-    plan:
-        artifacts:
-            name: plan
-            paths:
-            - ${CI_PROJECT_DIR}/plan.cache
-            reports:
-                terraform: ${CI_PROJECT_DIR}/plan.json
-
-        description: "Report what changes are going to be made to Gitlab CI schedules, based on the content of schedules.yml"
-        script:
-        - >-
-            gitlab-terraform plan
-            -var "GITLAB_PROJECT_ID=${CI_PROJECT_ID}"
-            -var "GITLAB_DEFAULT_BRANCH=${CI_DEFAULT_BRANCH}"
-            -var "JOBGRAPH_BOT_GITLAB_TOKEN=${JOBGRAPH_BOT_GITLAB_TOKEN}"
-            -var "SCHEDULES_YML_PATH=${CI_PROJECT_DIR}/gitlab-ci/schedules.yml"
-        - gitlab-terraform plan-json
-        - mv "${TF_ROOT}"/plan.* "${CI_PROJECT_DIR}"
-
-    apply:
-        description: "Change Gitlab CI schedules, based on the content of schedules.yml"
-        environment:
-            name: jobgraph
-
-        script:
-        - mv "${CI_PROJECT_DIR}/plan.cache" "${TF_ROOT}"
-        # No need to provide variable because it is going to reuse the existing cached plan.
-        - gitlab-terraform apply
-
-        upstream_dependencies: {jobgraph_schedules: "plan"}