add dev mode where warnings don't fail the test

Author: zeitlinger

conventions/src/main/kotlin/otel.java-conventions.gradle.kts

@@ -73,12 +73,13 @@ tasks.withType<JavaCompile>().configureEach {
           // We suppress the "options" warning because it prevents compilation on modern JDKs
           "-Xlint:-options",
           // jdk21 generates more serial warnings than previous versions
-          "-Xlint:-serial",
-
-          // Fail build on any warning
-          "-Werror"
+          "-Xlint:-serial"
         )
       )
+      if (System.getProperty("dev") != "true") {
+        // Fail build on any warning
+        compilerArgs.add("-Werror")
+      }
       val defaultJavaVersion = otelJava.maxJavaVersionSupported.getOrElse(DEFAULT_JAVA_VERSION).majorVersion.toInt()
       if (Math.max(otelJava.minJavaVersionSupported.get().majorVersion.toInt(), defaultJavaVersion) >= 21) {
         // new warning in jdk21