test: ensure erlang 23 in github action

.github/workflows/run_fvt_tests.yaml

@@ -16,6 +16,10 @@ jobs:
 
         steps:
         - uses: actions/checkout@v1
+        - uses: gleam-lang/setup-erlang@v1.1.2
+          id: install_erlang
+          with:
+            otp-version: 23.2
         - name: prepare
           run: |
             if make emqx-ee --dry-run > /dev/null 2>&1; then
@@ -52,7 +56,7 @@ jobs:
             output=$(docker exec -i node1.emqx.io bash -c "cat data/loaded_plugins" | tail -n1)
             if [ "$expected" != "$output" ]; then
                 exit 1
-            fi    
+            fi
         - name: make paho tests
           run: |
             if ! docker exec -i python /scripts/pytest.sh; then