ci: fix bad indentation

the ci job on #211 showed green,
but after it was merged devel failed. how?

Author: Paul Dreik

.github/workflows/clang18.yml

@@ -33,31 +33,31 @@ jobs:
         with:
           path: '**/*.log'
 
-cmake:
-  name: Compiles with clang 18, using cmake
-  runs-on: ubuntu-24.04
+  cmake:
+    name: Compiles with clang 18, using cmake
+    runs-on: ubuntu-24.04
 
-  steps:
-    - name: checkout
-      uses: actions/checkout@v4
-    - name: install packages
-      run: |
-        sudo apt install \
-          build-essential \
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+      - name: install packages
+        run: |
+          sudo apt install \
+            build-essential \
+            cmake \
+            nettle-dev \
+            libxxhash-dev \
+            libcatch2-dev \
+            time \
+            clang-18
+      - name: configure
+        run: |
           cmake \
-          nettle-dev \
-          libxxhash-dev \
-          libcatch2-dev \
-          time \
-          clang-18
-    - name: configure
-      run: |
-        cmake \
-          -B build \
-          -S inofficial_cmake/ \
-          -DCMAKE_COMPILE_WARNING_AS_ERROR=On \
-          -DCMAKE_CXX_COMPILER=clang++-18
-    - name: build
-      run: cmake --build build
-    - name: test
-      run: ctest --test-dir build --output-on-failure
+            -B build \
+            -S inofficial_cmake/ \
+            -DCMAKE_COMPILE_WARNING_AS_ERROR=On \
+            -DCMAKE_CXX_COMPILER=clang++-18
+      - name: build
+        run: cmake --build build
+      - name: test
+        run: ctest --test-dir build --output-on-failure