Update per-iteration JSON files for mkFit configuration (121X)

[mmasciov]

Update of per-iteration JSON files for mkFit configuration, as per PR cms-sw/cmsdist#7217 and cms-sw/cmssw#34921

[cmsbuild]

A new Pull Request was created by @mmasciov (Mario Masciovecchio) for branch main.

@perrotta, @smuzaffar, @iarspider, @mrodozov, @cmsbuild, @slava77, @jpata can you please review it and eventually sign? Thanks.
@makortel, @felicepantaleo, @GiacomoSguazzoni, @JanFSchulte, @rovere, @VinInn, @ebrondol, @gpetruc, @mmusich, @mtosi, @dgulhan this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.
cms-bot commands are listed here

[jpata]

+reconstruction

• tested in Update of mkFit for 12_1_0_pre2 cms-sw/cmssw#34921 (comment)

[mrodozov]

+externals

[mrodozov]

abort

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next main IBs after it passes the integration tests. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[mrodozov]

@jpata this is good to get in regardless of the cmssw PR ?

[jpata]

I believe this should be merged just before the corresponding CMSSW PR. For the moment we can wait until that one is signed.

[jpata]

@mrodozov from the reco point of view, this could be merged now, concurrently with cms-sw/cmssw#34921 (once it's fully signed).

[mrodozov]

I was asking if this is final so we can tag it and prepare the cmsdist change

[mmasciov]

I was asking if this is final so we can tag it and prepare the cmsdist change

Just to confirm that no further change is expected before the next pre-release.
All changes for the next pre-release are in this PR, together with cms-sw/cmsdist#7229 and cms-sw/cmssw#34921