github actions: verify schema against generated file

.github/workflows/tests.yml

@@ -49,3 +49,18 @@ jobs:
         with:
           command: clippy
           args: -- -D warnings
+
+  flatbuffers:
+    name: Check FlatBuffers generated file
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+      - name: Install flatc
+        uses: awalsh128/cache-apt-pkgs-action@latest
+        with:
+          packages: flatbuffers-compiler
+      - name: Generate rust code from schema
+        run: flatc --rust schema/lrs.fbs
+      - name: Ensure same output as commited
+        run: diff src/lrs_generated.rs lrs_generated.rs