Add RPM jobs as upstream of upload jobs

[cottsay]

In addition to adding the sync-packages-to-main-rpm jobs, this change also adds the (currently unused) import_upstream_rpm job.

Diff:

Updating job 'upload_main' (dry run)
    <<<
    --- remote config
    +++ new config
    @@ -26 +26 @@
    -      <upstreamProjects>Hrel_sync-packages-to-main,Irel_sync-packages-to-main,Jrel_sync-packages-to-main,Rrel_sync-packages-to-main,import_upstream</upstreamProjects>
    +      <upstreamProjects>Hrel_sync-packages-to-main,Hrel_sync-packages-to-main-rpm,Irel_sync-packages-to-main,Irel_sync-packages-to-main-rpm,Jrel_sync-packages-to-main,Jrel_sync-packages-to-main-rpm,Rrel_sync-packages-to-main,Rrel_sync-packages-to-main-rpm,import_upstream,import_upstream_rpm</upstreamProjects>
    >>>
Updating job 'upload_testing' (dry run)
    <<<
    --- remote config
    +++ new config
    @@ -26 +26 @@
    -      <upstreamProjects>Hrel_sync-packages-to-testing_8_x86_64,Hrel_sync-packages-to-testing_jammy_amd64,Hrel_sync-packages-to-testing_jammy_arm64,Irel_sync-packages-to-testing_9_x86_64,Irel_sync-packages-to-testing_jammy_amd64,Irel_sync-packages-to-testing_jammy_arm64,Jrel_sync-packages-to-testing_9_x86_64,Jrel_sync-packages-to-testing_noble_amd64,Jrel_sync-packages-to-testing_noble_arm64,Rrel_sync-packages-to-testing_9_x86_64,Rrel_sync-packages-to-testing_noble_amd64,Rrel_sync-packages-to-testing_noble_arm64,import_upstream</upstreamProjects>
    +      <upstreamProjects>Hrel_sync-packages-to-testing_8_x86_64,Hrel_sync-packages-to-testing_jammy_amd64,Hrel_sync-packages-to-testing_jammy_arm64,Irel_sync-packages-to-testing_9_x86_64,Irel_sync-packages-to-testing_jammy_amd64,Irel_sync-packages-to-testing_jammy_arm64,Jrel_sync-packages-to-testing_9_x86_64,Jrel_sync-packages-to-testing_noble_amd64,Jrel_sync-packages-to-testing_noble_arm64,Rrel_sync-packages-to-testing_9_x86_64,Rrel_sync-packages-to-testing_noble_amd64,Rrel_sync-packages-to-testing_noble_arm64,import_upstream,import_upstream_rpm</upstreamProjects>
    >>>

Fixes #882

FYI @marcoag

[cottsay]

This has been deployed to build.ros2.org.