build.yml in numo-openblas-0.4.0

- old
+ new

@@ -6,10 +6,10 @@
   build:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.5', '2.6', '2.7', '3.0' ]
+        ruby: [ '2.6', '2.7', '3.0' ]
     steps:
       - uses: actions/checkout@v2
       - name: Install gcc and gfortran
         run: sudo apt-get install -y gcc gfortran
       - name: Set up Ruby ${{ matrix.ruby }}