Fix CXX uppercase bug in ci

Signed-off-by: Raül <raulojeda@eprosima.com>

Author: raulojeda22

.github/workflows/reusable-sanitizers-ci.yml

@@ -359,7 +359,7 @@ jobs:
       TSAN_OPTIONS: second_deadlock_stack=1 history_size=7 memory_limit_mb=5000
       # TODO
       CC: gcc-12
-      cxx: g++-12
+      CXX: g++-12
     steps:
       - name: Free disk space
         uses: eProsima/eProsima-CI/ubuntu/free_disk_space@v0

.github/workflows/reusable-ubuntu-ci.yml

@@ -767,7 +767,7 @@ jobs:
     env:
       # TODO
       CC: gcc-11
-      cxx: g++-11
+      CXX: g++-11
     strategy:
       fail-fast: false
       matrix: