Disable errorprone RequestExplicitNullMarking (#7890)

Author: trask

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

@@ -88,6 +88,7 @@ tasks {
         // We annotate packages with @ParametersAreNonnullByDefault from com.google.code.findbugs:jsr305.
         // @NullMarked is the equivalent from jspecify.
         disable("AddNullMarkedToPackageInfo")
+        disable("RequireExplicitNullMarking")
 
         // This check causes too many changes to be introduced at once to be manageable.
         disable("SuppressWarningsWithoutExplanation")