Added support for jdk-21 (opensearch-project#500)

* Added support for jdk-21

Signed-off-by: Martin Gaievski <gaievski@amazon.com>
Signed-off-by: Gopala-Krishna.Char <gopala-krishna.char@intrafind.de>

.github/workflows/CI.yml

@@ -21,7 +21,7 @@ jobs:
     needs: Get-CI-Image-Tag
     strategy:
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [ubuntu-latest]
 
     name: Gradle Check Linux
@@ -55,7 +55,7 @@ jobs:
   Check-neural-search-windows:
     strategy:
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [windows-latest]
 
     name: Gradle Check Windows
@@ -82,7 +82,7 @@ jobs:
   Precommit-neural-search:
     strategy:
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [ubuntu-latest]
 
     name: Pre-commit Linux
@@ -116,7 +116,7 @@ jobs:
   Precommit-neural-search-windows:
     strategy:
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [windows-latest]
 
     name: Pre-commit Windows