Add CT tests to CI

Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>

.github/workflows/ct-tests.yml

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: Apache-2.0
+
+name: Constant-time tests
+permissions:
+  contents: read
+on:
+  workflow_dispatch:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+
+jobs:
+  check-ct:
+    name: Constant-time test
+    strategy:
+      matrix:
+        system: [ubuntu-latest, ubuntu-24.04-arm]
+    runs-on: ${{ matrix.system }}
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: ./.github/actions/setup-apt
+        with:
+          packages: valgrind
+      - name: Build and run test (-O3)
+        uses: ./.github/actions/ct-test
+        with: 
+          cflags: -O3
+      - name: Build and run test (-Os)
+        uses: ./.github/actions/ct-test
+        with: 
+          cflags: -Os