Fix gcc-13 build

Author: mborland

.github/workflows/ci.yml

@@ -83,6 +83,7 @@ jobs:
             os: ubuntu-22.04
             install:
               - g++-13-multilib
+            cxxflags: -Wno-uninitialized
           - toolset: gcc-12
             cxxstd: "03-gnu,11-gnu,14-gnu,17-gnu,20-gnu,23-gnu"
             address_model: "32"