don't test Clang 19 just yet; fix cancel-in-progres

.github/generate-job-matrix.py

@@ -89,7 +89,7 @@ configs = {
     for c in [make_gcc_config(ver) for ver in [12, 13, 14]]
     + [
         make_clang_config(ver, platform)
-        for ver in [16, 17, 18, 19]
+        for ver in [16, 17, 18]
         for platform in ["x86-64", "arm64"]
     ]
     + [make_apple_clang_config(ver) for ver in [15]]

.github/workflows/ci-clang-tidy.yml

@@ -34,20 +34,17 @@ on:
     paths-ignore:
       - "docs/**"
 
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  cancel-previous:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.ref }}
-      cancel-in-progress: true
-    runs-on: ubuntu-24.04
-    steps:
-      - run: echo "Cancelling all previous runs of ${{ github.workflow }}-${{ github.ref }}"
   generate-matrix:
     name: "Generate build matrix for ${{ github.workflow }}"
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     runs-on: ubuntu-24.04
-    needs: cancel-previous
     steps:
       - name: Set up Python
         uses: actions/setup-python@v5

.github/workflows/ci-conan.yml

@@ -33,20 +33,16 @@ on:
 env:
   CHANNEL: ${{ fromJSON('["testing", "stable"]')[github.ref_type == 'tag' && startsWith(github.ref_name, 'v')] }}
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  cancel-previous:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.ref }}
-      cancel-in-progress: true
-    runs-on: ubuntu-24.04
-    steps:
-      - run: echo "Cancelling all previous runs of ${{ github.workflow }}-${{ github.ref }}"
   generate-matrix:
     name: "Generate build matrix for ${{ github.workflow }}"
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     runs-on: ubuntu-24.04
-    needs: cancel-previous
     steps:
       - name: Set up Python
         uses: actions/setup-python@v5

.github/workflows/ci-freestanding.yml

@@ -34,20 +34,16 @@ on:
     paths-ignore:
       - "docs/**"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  cancel-previous:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.ref }}
-      cancel-in-progress: true
-    runs-on: ubuntu-24.04
-    steps:
-      - run: echo "Cancelling all previous runs of ${{ github.workflow }}-${{ github.ref }}"
   generate-matrix:
     name: "Generate build matrix for ${{ github.workflow }}"
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     runs-on: ubuntu-24.04
-    needs: cancel-previous
     steps:
       - name: Set up Python
         uses: actions/setup-python@v5

.github/workflows/ci-test-package-cmake.yml

@@ -38,20 +38,16 @@ on:
       - "example/**"
       - "test/**"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
-  cancel-previous:
-    concurrency:
-      group: ${{ github.workflow }}-${{ github.ref }}
-      cancel-in-progress: true
-    runs-on: ubuntu-24.04
-    steps:
-      - run: echo "Cancelling all previous runs of ${{ github.workflow }}-${{ github.ref }}"
   generate-matrix:
     name: "Generate build matrix for ${{ github.workflow }}"
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     runs-on: ubuntu-24.04
-    needs: cancel-previous
     steps:
       - name: Set up Python
         uses: actions/setup-python@v5