Include linux matrix configuration in cache key

Author: bauer-andreas

.github/workflows/build-and-test.yml

@@ -72,7 +72,7 @@ jobs:
     - uses: actions/cache@v2
       with:
         path: .build
-        key: ${{ runner.os }}-${{matrix.linux}}-spm-${{ hashFiles('Package.resolved') }}
+        key: ${{ runner.os }}-${{matrix.linux}}-${{matrix.configuration}}-spm-${{ hashFiles('Package.resolved') }}
     - name: Check Swift version
       run: swift --version
     - name: Release Build