Add CI for code

.github/workflows/code.yml

@@ -0,0 +1,26 @@
+name: Tests
+
+on: [push]
+
+jobs:
+  compile:
+    name: Execute tests
+    runs-on: ubuntu-latest
+    container:
+      image: ocaml/opam:debian
+      options: --user root
+    steps:
+      - name: initialize
+        run: opam init --disable-sandboxing && opam update && apt update
+      - name: pin frama-c
+        run: opam pin frama-c --dev-repo -n
+      - name: install frama-c
+        run: opam depext frama-c && opam install frama-c && eval $(opam env)
+      - name: install z3
+        run: apt install z3
+      - name: configure Why3
+        run: why3 config detect
+      - name: retrieve sources
+        uses: actions/checkout@v4
+      - name: tests
+        run: cd code && make prepare-tests && make run-tests