Applied workaround to github workspace issue

.github/workflows/unit-tests.yml

@@ -48,6 +48,10 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
+    # Necessary due to https://github.com/actions/runner/issues/2058
+    - name: Save workspace to environment
+      run: echo "GITHUB_WORKSPACE=$GITHUB_WORKSPACE" >> $GITHUB_ENV
+
     - name: Update package cache
       run: apt update -y
 
@@ -66,7 +70,7 @@ jobs:
       id: strings
       shell: bash
       run: |
-        echo "build-output-dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
+        echo "build-output-dir=${{ env.GITHUB_WORKSPACE }}/build" >> "$GITHUB_OUTPUT"
 
     - name: Configure CMake
       run: >
@@ -76,7 +80,7 @@ jobs:
         -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
         -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
         -DSPICY_PROTOBUF_TEST=ON
-        -S ${{ github.workspace }}
+        -S ${{ env.GITHUB_WORKSPACE }}
 
     - name: Build
       run: cmake --build ${{ steps.strings.outputs.build-output-dir }} --config ${{ matrix.build_type }}