fixup version value (#178)

Author: skykanin

pom.xml

@@ -130,7 +130,7 @@
     <dependency>
         <groupId>io.micronaut.tracing</groupId>
         <artifactId>micronaut-tracing-annotation</artifactId>
-        <version>7.2.0</version>
+        <version>${micronaut.tracing.version}</version>
     </dependency>
     <dependency>
       <groupId>io.micronaut.cache</groupId>