CI: build on JDK 25; update Gradle to 9.4.1 (#12)

Gradle 9 is required for JDK 25 and now needs the JUnit Platform launcher
declared explicitly. The CI matrix moves to 17/21/25 (Gradle 9 requires JDK 17+
to run; the library still targets Java 11). Adds a .gitignore (the repo had none).

Author: FlorianKirmaier

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
   build:
     strategy:
       matrix:
-        jdk: [11, 17, 21]
+        jdk: [17, 21, 25]
 
     runs-on: ubuntu-latest
 

.gitignore

@@ -0,0 +1,6 @@
+.gradle/
+build/
+.idea/
+.tmp/
+*.hprof
+heapdump_jmemb_*.hprof

build.gradle

@@ -42,6 +42,7 @@ dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-api:$JUNIT_VERSION"
     testImplementation "org.junit.jupiter:junit-jupiter-params:$JUNIT_VERSION"
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$JUNIT_VERSION"
+    testRuntimeOnly "org.junit.platform:junit-platform-launcher:1.11.3" // required explicitly since Gradle 9
     testRuntimeOnly "ch.qos.logback:logback-classic:$LOGBACK_VERSION"
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME