NMS-19535: Don't disable rpm's internal dependency generator

[dino2gnt]

Setting %define _use_internal_dependency_generator 0 is broken as of rpm v6, and will result in failure:

error: External dependency generator is incompatible with v6 packages

External dependency generation has been removed in rpm format v6, hence internal dependency generation must be allowed.

I frequently build in an environment that packages using a much newer rpm and setting this to 0 broke those builds. Removing _use_internal_dependency_generator 0 allows the rpm build to complete and doesn't appear to have any deleterious effects aside from the two fixes noted below.

This adds a specific exclude for an ancient libstdc++-libc6.2 that "something" we're packing depends on that I assume the internal dependency generator discovered, and in addition adds an explicit Provides: for the user and group for core, minion, and sentinel, the lack of which appeared to cause an issue where we somehow Requires: user(opennms) that couldn't resolve because none of the packages Provides: it.

External References

• Jira (Issue Tracker): https://opennms.atlassian.net/browse/NMS-19535
• Drop support for external dependency generator for v6 packages rpm-software-management/rpm#2373