ci: add bootstrap stack for python@3.6:3.13 (#47719)

Resurrect latest Python 3.6
Add clingo-bootstrap to Gitlab CI.

share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml

@@ -951,3 +951,49 @@ windows-vis-build:
   needs:
     - artifacts: True
       job: windows-vis-generate
+
+#######################################
+# Bootstrap x86_64-linux-gnu
+#######################################
+.bootstrap-x86_64-linux-gnu:
+  extends: [ ".linux_x86_64_v3" ]
+  variables:
+    SPACK_CI_STACK_NAME: bootstrap-x86_64-linux-gnu
+
+bootstrap-x86_64-linux-gnu-generate:
+  extends: [ .generate-x86_64, .bootstrap-x86_64-linux-gnu ]
+  image: ghcr.io/spack/ubuntu-24.04:v2024-09-05-v2
+
+bootstrap-x86_64-linux-gnu-build:
+  extends: [ .build, .bootstrap-x86_64-linux-gnu ]
+  trigger:
+    include:
+      - artifact: jobs_scratch_dir/cloud-ci-pipeline.yml
+        job: bootstrap-x86_64-linux-gnu-generate
+    strategy: depend
+  needs:
+    - artifacts: True
+      job: bootstrap-x86_64-linux-gnu-generate
+
+#######################################
+# Bootstrap aarch64-darwin
+#######################################
+.bootstrap-aarch64-darwin:
+  extends: [.darwin_aarch64]
+  variables:
+    SPACK_CI_STACK_NAME: bootstrap-aarch64-darwin
+
+bootstrap-aarch64-darwin-generate:
+  tags: [macos-ventura, apple-clang-15, aarch64-macos]
+  extends: [.bootstrap-aarch64-darwin, .generate-base]
+
+bootstrap-aarch64-darwin-build:
+  extends: [.bootstrap-aarch64-darwin, .build]
+  trigger:
+    include:
+      - artifact: jobs_scratch_dir/cloud-ci-pipeline.yml
+        job: bootstrap-aarch64-darwin-generate
+    strategy: depend
+  needs:
+    - artifacts: true
+      job: bootstrap-aarch64-darwin-generate

share/spack/gitlab/cloud_pipelines/stacks/bootstrap-aarch64-darwin/spack.yaml

@@ -0,0 +1,33 @@
+spack:
+  view: false
+
+  packages:
+    all:
+      require: target=aarch64
+
+  config:
+    deprecated: true  # allow old python versions
+
+  specs:
+  - clingo-bootstrap +optimized ^python@3.13
+  - clingo-bootstrap +optimized ^python@3.12
+  - clingo-bootstrap +optimized ^python@3.11
+  - clingo-bootstrap +optimized ^python@3.10
+  - clingo-bootstrap +optimized ^python@3.9
+  - clingo-bootstrap +optimized ^python@3.8
+
+  - clingo-bootstrap@spack +optimized ^python@3.13
+  - clingo-bootstrap@spack +optimized ^python@3.12
+  - clingo-bootstrap@spack +optimized ^python@3.11
+  - clingo-bootstrap@spack +optimized ^python@3.10
+  - clingo-bootstrap@spack +optimized ^python@3.9
+  - clingo-bootstrap@spack +optimized ^python@3.8
+
+  ci:
+    pipeline-gen:
+    - build-job-remove:
+        tags: [spack, public]
+    - build-job:
+        variables:
+          CI_GPG_KEY_ROOT: /etc/protected-runner
+        tags: [macos-ventura, apple-clang-15, aarch64-macos]

share/spack/gitlab/cloud_pipelines/stacks/bootstrap-x86_64-linux-gnu/spack.yaml

@@ -0,0 +1,35 @@
+spack:
+  view: false
+
+  packages:
+    all:
+      require: target=x86_64_v3
+
+  config:
+    deprecated: true  # allow old python versions
+
+  specs:
+  - clingo-bootstrap +optimized ^python@3.13
+  - clingo-bootstrap +optimized ^python@3.12
+  - clingo-bootstrap +optimized ^python@3.11
+  - clingo-bootstrap +optimized ^python@3.10
+  - clingo-bootstrap +optimized ^python@3.9
+  - clingo-bootstrap +optimized ^python@3.8
+  - clingo-bootstrap +optimized ^python@3.7
+  - clingo-bootstrap +optimized ^python@3.6
+
+  - clingo-bootstrap@spack +optimized ^python@3.13
+  - clingo-bootstrap@spack +optimized ^python@3.12
+  - clingo-bootstrap@spack +optimized ^python@3.11
+  - clingo-bootstrap@spack +optimized ^python@3.10
+  - clingo-bootstrap@spack +optimized ^python@3.9
+  - clingo-bootstrap@spack +optimized ^python@3.8
+  - clingo-bootstrap@spack +optimized ^python@3.7
+  - clingo-bootstrap@spack +optimized ^python@3.6
+
+  ci:
+    pipeline-gen:
+    - build-job:
+        image:
+          name: ghcr.io/spack/ubuntu-24.04:v2024-09-05-v2
+          entrypoint: ['']