CI updates (#706)

* Add a TRACING build to CI

* Update MacOS version

.github/workflows/main.yml

@@ -67,6 +67,11 @@ jobs:
             build-type: Debug
             self-host: true
             extra-cmake-flags: "-DSNMALLOC_USE_PTHREAD_DESTRUCTORS=On -DCMAKE_CXX_COMPILER=clang++-10 -DCMAKE_C_COMPILER=clang-10"
+          - os: "ubuntu-20.04"
+            variant: "Traced Build"
+            build-type: Release
+            extra-cmake-flags: "-DSNMALLOC_TRACING=On"
+            build-only: yes
           - os: "ubuntu-20.04"
             variant: "clang-10 libstdc++ (Build only)"
             build-type: Release
@@ -111,7 +116,7 @@ jobs:
   macos:
     strategy:
       matrix:
-        os: [ "macos-12", "macos-14" ]
+        os: [ "macos-13", "macos-14", "macos-15" ]
         build-type: [ "Release", "Debug" ]
         extra-cmake-flags: [ "", "-DSNMALLOC_USE_CXX17=ON" ]
       fail-fast: false