CI: update minimum tested Java from 8 to 11

Unfortunately, OpenJDK 8 tests crash now.

See also imagej/pyimagej@e241aa5.

Author: ctrueden

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
       matrix:
         platform: [ubuntu-latest, windows-latest, macos-latest]
         python-version: ['3.9', '3.12']
-        java-version: ['8', '21']
+        java-version: ['11', '21']
 
     steps:
       - uses: actions/checkout@v4