adds conan caching to gh action

Author: eyck

.github/workflows/ci-compile.yml

@@ -38,6 +38,12 @@ jobs:
           path: ~/.conan2
           key: conan-${{ runner.os }}-unit-cpp${{ matrix.cpp_std }}-${{ hashFiles('conanfile.py') }}
 
+      - name: Cache Conan
+        uses: actions/cache@v4
+        with:
+          path: ~/.conan2
+          key: conan-${{ runner.os }}-unit-cpp${{ matrix.cpp_std }}-${{ hashFiles('conanfile.py') }}
+
       - name: Install dependencies
         run: |
           sudo apt-get update