Add valgrind test

.github/workflows/test.yml

@@ -6,7 +6,7 @@ jobs:
     steps:
     - uses: actions/checkout@v3
     - name: Install packages
-      run: sudo apt-get install libmbedtls-dev
+      run: sudo apt-get install libmbedtls-dev valgrind
     - name: gcc
       run: make test test++ IPV6=0 CC=gcc
     - name: clang
@@ -15,6 +15,8 @@ jobs:
       run: make test SSL=OPENSSL IPV6=0
     - name: unamalgamated
       run: make unamalgamated
+    - name: valgrind
+      run: make valgrind
   examples:
     runs-on: ubuntu-latest
     steps: