Build with JDK 24 (JVM requirements of JARs unchanged)

* GHA gradle.yml
** Install both 23 (to launch Gradle) and 24 (to compile Java)
** disable build_nix


* gradle.properties
** Require JDK 24

.github/workflows/gradle.yml

@@ -18,7 +18,7 @@ jobs:
         os: [ubuntu-24.04, ubuntu-24.04-arm, macOS-14]
         distribution: ['temurin']
       fail-fast: false
-    name: ${{ matrix.os }} JDK 23
+    name: ${{ matrix.os }} JDK 24 (via Gradle Java toolchains)
     steps:
       - name: Git checkout
         uses: actions/checkout@v4
@@ -28,6 +28,7 @@ jobs:
           distribution: ${{ matrix.distribution }}
           # When installing multiple JDKs, the last JDK installed is the default and will be used to run Gradle itself
           java-version: |
+            24-ea
             23
           cache: 'gradle'
       - name: Install Nix
@@ -43,6 +44,7 @@ jobs:
 
 
   build_nix:
+    if: false  # Disabled until JDK 24 is in nixpkgs
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:

gradle.properties

@@ -1,14 +1,14 @@
 secpVersion = 0.0.1
 
 # Major (whole number) version of JDK to use for javac, jlink, jpackage, etc.
-javaToolchainVersion = 23
+javaToolchainVersion = 24
 # Vendor for javaToolChain. (Should be indicator string from Gradle's KnownJvmVendor enum or empty string)
 # Official builds use 'Eclipse Adoptium'
 #javaToolchainVendor = Eclipse Adoptium
 javaToolchainVendor =
 
 # Where to look for JDKs (via environment variables)
-org.gradle.java.installations.fromEnv = JAVA_HOME, JDK23
+org.gradle.java.installations.fromEnv = JAVA_HOME, JDK24
 
 # Auto-detection can be disabled if you have multiple JDKs of the
 # same version installed and Gradle won't reliably select the version you actually want