Drop Java 8 for Linux. Move Windows build to Java 11.

Author: markt-asf

.github/workflows/ci.yml

@@ -28,11 +28,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: [ 8, 11, 16, 17-ea ]
+        java: [ 11, 16, 17-ea ]
         os: [ ubuntu-latest ]
         include:
         - os: windows-latest
-          java: 8
+          java: 11
     name: JDK${{ matrix.java }} ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     steps: