ci: build once with HEALTH=1 as well

Code behind a build flag nobody sets in CI rots quietly. One extra build of
the same machine with the instrumentation on keeps it compiling.

.github/workflows/build.yml

@@ -26,3 +26,5 @@ jobs:
         run: make CI=1 MACHINE="KP_9000_6XHML_X2"
       - name: Make project (8x1/RTL8373)
         run: make CI=1 MACHINE="KP_9000_9XHML_X_V3_1"
+      - name: Make project with the health instrumentation
+        run: make clean && make CI=1 MACHINE="KP_9000_6XHML_X2" HEALTH=1