Update jdk in github workflows config

Changed jdk version from 17 to 21 since 17 is EOL now.

Signed-off-by: Siddharth Srinivasan <[email protected]>

Author: sid-srini

.github/workflows/main.yml

@@ -40,7 +40,7 @@ jobs:
     timeout-minutes: 60
     strategy:
       matrix:
-        java: [ '17' ]
+        java: [ '21' ]
         os: [ ubuntu-latest ]
       fail-fast: false
     runs-on: ${{ matrix.os }}