[ci] add concurrency

.github/workflows/build_kernel.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build kernels (${{ matrix.arch }})

.github/workflows/build_kernel_macos.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build kernel

.github/workflows/build_kernel_rocm.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build kernels (ROCm)

.github/workflows/build_kernel_windows.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     strategy:

.github/workflows/build_kernel_xpu.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build kernel

.github/workflows/check_variants.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Check build variants

.github/workflows/kernel-builder-cli-docs.yaml

@@ -12,6 +12,10 @@ on:
     branches:
       - main
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check-cli-docs:
     runs-on: ubuntu-latest

.github/workflows/kernels_data_python_release.yaml

@@ -8,6 +8,7 @@
 #  - publish step switched from `uv publish` + API token to
 #    `PyO3/maturin-action` + PyPI trusted publishing (see plan.md §3a, §3b)
 #  - pull_request trigger gained `paths-ignore` for docs-only PRs
+#  - concurrency block added (cancel-in-progress only for PRs, never on tag/main)
 name: CI
 
 on:
@@ -23,6 +24,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 permissions:
   contents: read
 

.github/workflows/lint.yml

@@ -6,6 +6,10 @@ on:
       - "docs/**"
       - "*.md"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 env:
   RUFF_VERSION: "0.15.10"
   GRIFFE_VERSION: "1.15.0"

.github/workflows/nix_checks.yml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Nix checks

.github/workflows/rust.yaml

@@ -7,6 +7,10 @@ on:
       - "docs/**"
       - "*.md"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   fmt:
     name: Rustfmt

.github/workflows/test_e2e.yaml

@@ -13,6 +13,10 @@ on:
       - ".github/workflows/test_e2e.yaml"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 env:
   HF_ENDPOINT: https://hub-ci.huggingface.co
   HF_TOKEN: ${{ secrets.HF_HUB_CI_TOKEN }}

.github/workflows/test_extra_commands.yaml

@@ -10,6 +10,10 @@ on:
       - "*.md"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build kernel