Ccache setup

The goal is to speed up recompilation using ccache.

Ccache is a tool that speeds up recompilation of C/C++ code. It does this by caching the results of previous compilations.
When you recompile code, ccache checks if it has already compiled the same code with the same compiler flags. If so, it uses the cached result instead of recompiling.

.github/workflows/build_ubuntu_debug.yml

@@ -16,8 +16,15 @@ jobs:
         compiler: [g++-10, g++-9, g++-8, g++-7, clang-6, clang-7, clang-8, clang-9, clang-10, clang-11, clang-12] 
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     
+    - name: Caching objects
+      id: cache-objects
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/ccache
+        key: ${{ runner.os }}-${{env.BUILD_TYPE}}-${{ matrix.compiler }}-objects
+
     - name: Install Dependencies
       shell: bash
       run: |