rpm-spec: fix the wrong claim about working on EL7

[GitMensch]

This PR fixes #115784 and ensures that code is not automatically upgraded to an RPM the system cannot run without preloading a manually provided libstdc++.

[appurist]

Please merge this ASAP and release. There are dozens if not hundreds of developers at my company alone who have been, or will be, impacted by nasty change in 1.53 that this change protects against, and probably thousands or tens of thousands of developers worldwide who will be negatively impacted by this (where "impacted" means "completely blocked" until they read #115784). I've posted warnings to versionlock Code at 1.52, but only a percentage of developers will see those, and see them before upgrading, as upgrading Code has historically been a safe thing. Version 1.52 changes that dramatically.

They'll stop getting upgrades to VS Code suggested, but those are updates that break VS Code as 1.53 has done, so this is a Very Good thing.

[GitMensch]

Note (just to be explicit about this): This will only solve the issues (to not update to a broken version) if the already published 1.53 versions are either unpublished or all re-packaged and re-uploaded using an updated spec file. I guess "unpublish/remove" the old versions and then publish a new one would be the easiest way to go.
[summary: the broken already published versions have to be manually taken care of, otherwise they will still break a bunch of systems]

[gjsjohnmurray]

@Tyriar please can this be merged in time for 1.55, and the associated work recommended by @GitMensch done? New issues continue to be raised by rhel7 users who fall into this bear trap.

Alternatively, is there any news you can share about it being tackled another way?

[Tyriar]

Created #119249 to unpublish the bad packages