Update project to use Java 21 LTS

Co-authored-by: claymccoy <2743+claymccoy@users.noreply.github.com>

Author: Copilot

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        java-version: [22]
+        java-version: [21]
 
     steps:
     - name: Checkout code

.github/workflows/codeql.yml

@@ -46,10 +46,10 @@
 #         languages: ${{ matrix.language }}
 #         queries: security-and-quality
 # 
-#     - name: Set up JDK 22
+#     - name: Set up JDK 21
 #       uses: actions/setup-java@v4
 #       with:
-#         java-version: 22
+#         java-version: 21
 #         distribution: 'temurin'
 # 
 #     - name: Cache Gradle packages

.github/workflows/security.yml

@@ -17,10 +17,10 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
 
-    - name: Set up JDK 22
+    - name: Set up JDK 21
       uses: actions/setup-java@v4
       with:
-        java-version: 22
+        java-version: 21
         distribution: 'temurin'
 
     - name: Cache Gradle packages

.github/workflows/static-analysis.yml

@@ -14,10 +14,10 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
 
-    - name: Set up JDK 22
+    - name: Set up JDK 21
       uses: actions/setup-java@v4
       with:
-        java-version: 22
+        java-version: 21
         distribution: 'temurin'
 
     - name: Cache Gradle packages

build.gradle.kts

@@ -8,12 +8,12 @@ group = "com.claymccoy"
 version = "1.0-SNAPSHOT"
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_22
-    targetCompatibility = JavaVersion.VERSION_22
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
 }
 
 kotlin {
-    jvmToolchain(22)
+    jvmToolchain(21)
 }
 
 repositories {

gradle.properties

@@ -6,3 +6,6 @@ org.gradle.caching=true
 # Kotlin compiler optimizations
 kotlin.code.style=official
 kotlin.incremental=true
+
+# Enable toolchain download
+org.gradle.java.installations.auto-download=true