Dependency convergence check misses non-compliance on the managed dependencies #3710
Description
Last Friday, I was almost releasing a Google Cloud BOM version that include an incompatibility.
In #3593, I found that com.google.cloud:google-cloud-spanner-jdbc:2.5.11 depended on google-cloud-spanner 6.18.0 while the google-cloud-spanner in the BOM was 6.19.0. This was non-compliance of the convergence rule. The two are not compatible (see the compilation error in googleapis/java-spanner-jdbc#752 (comment)). However the check didn't detect the gap, because google-cloud-spanner is part of the BOM and its version was set to 6.19.0.