Disable SystemOut errorprone check when running locally (#3579)

buildSrc/src/main/kotlin/otel.errorprone-conventions.gradle.kts

@@ -8,7 +8,8 @@ dependencies {
   errorprone("com.google.errorprone:error_prone_core")
 }
 
-val disableErrorProne = gradle.startParameter.projectProperties.get("disableErrorProne")?.toBoolean() ?: false
+val disableErrorProne = gradle.startParameter.projectProperties.get("disableErrorProne")?.toBoolean()
+  ?: false
 
 tasks {
   withType<JavaCompile>().configureEach {
@@ -20,6 +21,10 @@ tasks {
 
       excludedPaths.set(".*/build/generated/.*")
 
+      if (System.getenv("CI") == null) {
+        disable("SystemOut")
+      }
+
       // Doesn't work well with Java 8
       disable("FutureReturnValueIgnored")