Upgrade to OpenTelemetry 1.38.0

This aligns its version with that used by Micrometer Tracing 1.3.x.

Closes gh-43200

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -1550,7 +1550,7 @@ bom {
 				.formatted(version.toString().replace(".", "")))
 		}
 	}
-	library("OpenTelemetry", "1.37.0") {
+	library("OpenTelemetry", "1.38.0") {
 		group("io.opentelemetry") {
 			imports = [
 				"opentelemetry-bom"