ci: fix pipeline – remove container until arm64 image is rebuilt

The ci-cpp image was likely built for linux/amd64; the eulernest runner
is linux/arm64 (Raspberry Pi), so the container exited immediately
without running any steps (task 102 log: 10 lines, no step output).

Fix: run directly on the host runner and install cmake/g++ via apt-get
(same approach as the previously working workflow).

Also pin --platform=linux/arm64 in Dockerfile.ci-cpp so the next
image build produces the correct architecture. Once the image is pushed,
re-add the container: block to the workflow.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/docker/Dockerfile.ci-cpp

@@ -1,4 +1,4 @@
-FROM ubuntu:22.04
+FROM --platform=linux/arm64 ubuntu:22.04
 
 # Node.js 20 from NodeSource (Ubuntu Jammy ships v12 which is too old
 # for actions/checkout@v4 — static class blocks require Node.js >= 16).

.gitea/workflows/cpp-tests.yml

@@ -11,12 +11,17 @@ on:
 jobs:
   test:
     runs-on: eulernest
-    container:
-      image: git.eulernest.eu/conformallab/ci-cpp:latest
+    # container image intentionally omitted until ci-cpp:latest is
+    # rebuilt for linux/arm64 and pushed to git.eulernest.eu
 
     steps:
       - uses: actions/checkout@v4
 
+      - name: Install build tools
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y --no-install-recommends cmake g++ git ca-certificates
+
       - name: Configure (tests-only mode)
         run: cmake -S code -B build -DCMAKE_BUILD_TYPE=Release
 
@@ -37,6 +42,5 @@ jobs:
             failed=$(grep -o 'failures="[0-9]*"' test-results.xml | grep -o '[0-9]*' | head -1)
             skipped=$(grep -o 'skipped="[0-9]*"' test-results.xml | grep -o '[0-9]*' | head -1)
             passed=$(( ${total:-0} - ${failed:-0} - ${skipped:-0} ))
-            echo ""
             echo "TOTAL: ${total:-0} | PASSED: $passed | FAILED: ${failed:-0} | SKIPPED: ${skipped:-0}"
           fi