Switch C++ compatibility workflow to Ubuntu 22.04

Ubuntu latest (24.04) shows memory corruption in binary parser
that doesn't reproduce locally. Try older Ubuntu version.

.github/workflows/spine-cpp-compatibility.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-22.04, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4