Transitive Guava dependency in Stackdriver module is causing build failures

[shakuzen]

Following up on #3954, the Boot team reported that the stackdriver module is having the issue in their build, and a simple project building with the stackdriver module as a dependency reproduces the issue. Excluding the listenablefuture transitive dependency from the google-cloud-monitoring dependency (as suggested by @wilkinsona) seems to make the issue go away.

Could not resolve com.google.guava:guava:32.1.1-jre.
     Required by:
         project : > io.micrometer:micrometer-registry-stackdriver:1.12.0-SNAPSHOT > com.google.cloud:google-cloud-monitoring:3.23.0
      > Module 'com.google.guava:guava' has been rejected:
           Cannot select module with conflict on capability 'com.google.guava:listenablefuture:1.0' also provided by [com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava(runtime)]
   > Could not resolve com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava.