ci:build: use parallel_level

.github/workflows/ci_build.yml

@@ -3,7 +3,10 @@ name: build
 env:
   HOMEBREW_NO_INSTALL_CLEANUP: 1
   CTEST_NO_TESTS_ACTION: error
-  FC: gfortran-12
+  FC: gfortran-13
+  CTEST_PARALLEL_LEVEL: 4
+  CMAKE_BUILD_PARALLEL_LEVEL: 4
+
 
 on:
   push:
@@ -28,21 +31,11 @@ jobs:
     runs-on: ${{ matrix.os}}
 
     steps:
-
-    - name: prereqs (Linux)
-      if: runner.os == 'Linux'
-      run: sudo apt install --no-install-recommends ninja-build
-
-    - name: prereqs (MacOS)
-      if: runner.os == 'macOS'
-      run: brew install ninja
-
     - uses: actions/checkout@v4
 
     - name: Configure HDF5 library
       run: >-
         cmake
-        -GNinja
         -S scripts -B scripts/build
         --install-prefix ${{ runner.temp }}
         -DBUILD_SHARED_LIBS:BOOL=${{ matrix.shared }}