build: update Java version targets in ci

Author: WiIIiam278

.github/workflows/ci.yml

@@ -132,4 +132,4 @@ jobs:
             fabric
           game-versions: |
             1.21
-          java: 17
+          java: 21

.github/workflows/pr_tests.yml

@@ -15,10 +15,10 @@ jobs:
     steps:
       - name: 'Checkout for CI 🛎'
         uses: actions/checkout@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 with Gradle 🏗️'
         uses: gradle/gradle-build-action@v3

.github/workflows/release.yml

@@ -118,4 +118,4 @@ jobs:
             fabric
           game-versions: |
             1.21
-          java: 17
+          java: 21