cmake: enable -Werror=dev in dev-mode preset

CMakePresets.json

@@ -62,6 +62,7 @@
       "name": "dev-mode",
       "displayName": "Developer mode, with all features/dependencies enabled",
       "binaryDir": "${sourceDir}/build_dev_mode",
+      "errors": {"dev": true},
       "cacheVariables": {
         "BUILD_BENCH": "ON",
         "BUILD_CLI": "ON",