fix(mosq): Fix clean compilation addressing _GNU_SOURCE redefined

.github/workflows/mosq__build.yml

@@ -25,8 +25,6 @@ jobs:
         with:
           submodules: recursive
       - name: Build with IDF-${{ matrix.idf_ver }}
-        env:
-          EXPECTED_WARNING: "\"_GNU_SOURCE\" redefined"
         shell: bash
         run: |
           . ${IDF_PATH}/export.sh