Fix for builds broken by Xcode 16

[travis-mark]

I hope this format for the PR is okay, never contributed here before. I ran into this when our intern grouped the 3 files he was working on and broke builds. I rolled back the grouping in our project, but I wanted CocoaPods to be able to support it going forward.

Changes:

• Add object version 70 to version map
• Add support for new folder group type (PBXFileSystemSynchronizedRootGroup), currently an empty implementation to resolve error

Related Issues:

• RuntimeError - PBXGroup attempted to initialize an object with unknown ISA PBXFileSystemSynchronizedRootGroup from attributes: {"isa"=>"PBXFileSystemSynchronizedRootGroup", "explicitFileTypes"=>{}, "explicitFolders"=>[], "path"=>"AppIntents", "sourceTree"=>"<group>"} #950
• RuntimeError - PBXGroup attempted to initialize an object with unknown ISA PBXFileSystemSynchronizedRootGroup from attributes: {"isa"=>"PBXFileSystemSynchronizedRootGroup", "explicitFileTypes"=>{}, "explicitFolders"=>[], "path"=>"bike-taxi.eu", "sourceTree"=>"<group>"} #951
• CocoaPods pod init Fails with “Unknown ISA PBXFileSystemSynchronizedRootGroup” Error on Xcode 16 #963
• Version 16.0 (16A242d) And CocoaPods version:(1.15.2),Execute: pod init #965
• xcodeproj fails to initialize object from unknown ISA: PBXFileSystemSynchronizedRootGroup #966
• RuntimeError due to an ISA generated by Xcode #967
• RuntimeError - PBXGroup attempted to initialize an object with unknown ISA PBXFileSystemSynchronizedRootGroup #968
• Doesn’t support the new Xcode 16 folders format #969
• Cannot instal pod #974

[Brett-Best]

You may be interested in #942 :)

[sborovikov-belkacar]

I’ve checked this fix locally on my Mac within Fastlane in a project with the new Xcode folders format. It's working!

[igor-makarov]

@travis-mark I've looked at this PR, and while it fixes the crash, the underlying problem will not go away.

Since the FS-synchronized group is a new type with its own properties and child entities, Xcodeproj won't know how to output it. Which will cause the resulting project file to lose data.

I strongly recommend looking at #942 and perhaps helping out on it.