Use standard C-test workflows

Author: jeromekelleher

.github/workflows/tests.yml

@@ -18,6 +18,20 @@ jobs:
       working-directory: python
       cli-test-cmd: tskit --help
 
+  test-c:
+    name: C tests
+    uses: tskit-dev/.github/.github/workflows/c-tests.yml@v10
+    with:
+      library-directory: c
+    secrets: inherit
+
+  test-python-c:
+    name: Python-C tests
+    uses: tskit-dev/.github/.github/workflows/python-c-tests.yml@main
+    with:
+      pyproject-directory: python
+    secrets: inherit
+
   test:
     name: Python
     runs-on: ${{ matrix.os }}