only build headless when specifically requested

.github/workflows/package.yaml

@@ -28,7 +28,7 @@ jobs:
         if: ${{ runner.os == 'Linux' }}
         run: ./gradlew packageTarDistribution
       - name: Upload Artifacts
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         with:
           name: Sparrow Build - ${{ runner.os }}
           path: |

build.gradle

@@ -19,7 +19,7 @@ if(System.getProperty("os.arch") == "aarch64") {
     osArch = "aarch64"
     targetName = "-" + osArch
 }
-def headless = "true".equals(System.getProperty("java.awt.headless")) || GraphicsEnvironment.isHeadless()
+def headless = "true".equals(System.getProperty("java.awt.headless"))
 
 group "com.sparrowwallet"
 version "${sparrowVersion}"

buildSrc/src/main/java/org/openjfx/gradle/JavaFXPlatform.java

@@ -66,7 +66,7 @@ public enum JavaFXPlatform {
 
         String osClassifier = project.getExtensions().getByType(OsDetector.class).getClassifier();
 
-        if("true".equals(System.getProperty("java.awt.headless")) || GraphicsEnvironment.isHeadless()) {
+        if("true".equals(System.getProperty("java.awt.headless"))) {
             osClassifier += "-monocle";
         }