(improvement)(build) CI supports JDK 21. (#1548)

.github/workflows/windows-ci.yml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        java-version: [8, 11]
+        java-version: [8, 11, 21]  # Add JDK 21 to the matrix
 
     steps:
       - uses: actions/checkout@v2
@@ -23,7 +23,7 @@ jobs:
         uses: actions/setup-java@v2
         with:
           java-version: ${{ matrix.java-version }}
-          distribution: 'adopt'
+          distribution: 'adopt'  # You might need to change this if 'adopt' doesn't support JDK 21
 
       - name: Cache Maven packages
         uses: actions/cache@v2