Update CI Java version to 21

Author: thecatcore

.github/workflows/build_and_publish.yml

@@ -9,10 +9,10 @@
             fetch-depth: '0'
         - name: Validate Gradle Wrapper
           uses: gradle/actions/wrapper-validation@v4
-        - name: Set up JDK 17
+        - name: Set up JDK 21
           uses: actions/setup-java@v4
           with:
-            java-version: 17
+            java-version: 21
             distribution: temurin
 
         - name: Build

.github/workflows/pull_request.yml

@@ -7,10 +7,10 @@
         - uses: actions/checkout@v4
         - name: Validate Gradle Wrapper
           uses: gradle/actions/wrapper-validation@v4
-        - name: Set up JDK 17
+        - name: Set up JDK 21
           uses: actions/setup-java@v4
           with:
-            java-version: 17
+            java-version: 21
             distribution: temurin
 
         - name: Build