update github action to include PHP8.6

Author: nyamsprod

.github/workflows/build.yml

@@ -39,7 +39,7 @@ jobs:
               id: composer-cache
               run: |
                   echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
-            - uses: actions/cache@v4
+            - uses: actions/cache@v5
               with:
                   path: ${{ steps.composer-cache.outputs.dir }}
                   key: ${{ runner.os }}-composer-${{ matrix.stability }}-${{ matrix.flags }}-${{ hashFiles('**/composer.lock') }}