Explicitly set line endings to avoid using git at configuration time

Author: jjohannes

src/main/java/org/gradlex/conventions/check/SpotlessConventionsPlugin.java

@@ -18,6 +18,7 @@
 
 import com.diffplug.gradle.spotless.SpotlessExtension;
 import com.diffplug.gradle.spotless.SpotlessPlugin;
+import com.diffplug.spotless.LineEnding;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
 import org.gradlex.conventions.base.LifecycleConventionsPlugin;
@@ -45,16 +46,20 @@ public void apply(Project project) {
             java.targetExclude("build/**");
             java.palantirJavaFormat();
             java.licenseHeader("// SPDX-License-Identifier: Apache-2.0\n", "package|import");
+            java.setLineEndings(LineEnding.UNIX);
         });
+        // separate 'package-info' formatting due to https://github.com/diffplug/spotless/issues/532
         spotless.format("javaPackageInfoFiles", java -> {
-            java.targetExclude("build/**");
-            // add a separate extension due to https://github.com/diffplug/spotless/issues/532
+            java.targetExclude("build");
             java.target("src/**/package-info.java");
-
             java.licenseHeader("// SPDX-License-Identifier: Apache-2.0\n", "package|import|@");
+            java.setLineEndings(LineEnding.UNIX);
         });
 
         // format the build itself
-        spotless.kotlinGradle(gradle -> gradle.ktfmt().kotlinlangStyle().configure(conf -> conf.setMaxWidth(120)));
+        spotless.kotlinGradle(gradle -> {
+            gradle.ktfmt().kotlinlangStyle().configure(conf -> conf.setMaxWidth(120));
+            gradle.setLineEndings(LineEnding.UNIX);
+        });
     }
 }