Downgraded System.Collections.Immutable version requirement

3rd attempt at getting out a good release (or 4th for those of you who saw me briefly publish this release and then delete it again).
Me making mistakes during the release process is not unprecedented I might add (looking over my release history).
For this release I downgraded System.Collections.Immutable version requirements. I previously raised it to version 9.0.0 for no reason other than hey it's newer so must be better right? This pointless upgrade in dependency version requirements meant that if you are compiling a custom code analyzer you have to reference version 9 of System.Collections.Immutable as well, which may not be possible because you are dependent on the version the compiler loaded when it runs your analyzer, and so your custom code analyzer fails to load leaving you anxiously searching stackoverflow trying to work out why the version 9.0.0 System.Collections.Immutable.dll can't be loaded. At least I caught this early, earlier than the previous release would have been better, but the previous release was a Friday job, and I was tired. Hopefully this release, 2 days before Christmas, is more successful.

3.13 wasn't updated with the intended fixes

3.13 wasn't updated with the intended fixes, 3.14 now has the fixes that should have gone into 3.13

Fixed an issue with AddRange and RemoveRange not working

• Fixed an issue where items added using AddRange couldn't be removed using RemoveRange as raised in #35
• Updated the code to compile with .NET 8.0, made many small improvements
• Fixed an exception being caused because not everything that implements IList<T> can be cast to IList
• Updated all the nuget packages
• TargetFrameworks are now set in a Directory.Build.props
• nuget versions are now centrally managed in Directory.Pacakges.props

Added more constructors per feature request

Added a constructor that takes an enumerable to both:
ConcurrentObservableCollection
ConcurrentObservableSortedCollection
The former was in a feature request.

3.11 Added TryRemove to ConcurrentObservableDictionary

Merge pull request #26 from stewienj/25-concurrentobservabledictionar…

Fixes wrong action type being set in notify event

Fixes wrong action type being set in notify event in ConcurrentObservableSortedSet.Remove

HashSet and SortedSet now take custom Comparers

ConcurrentObservableHashSet can now take a custom IEqualityComparer.
ConcurrentObservableSortedSet can now take a custom IComparer.
Added a indexed getter to ConcurrentObservableSortedSet
Had to update .NET Framework 4.5 target to .NET Framework 4.51 because I couldn't find a 4.5 targeting pack on Microsoft's website.

Updated System.Collections.Immutable to v5.0.0

Updated System.Collections.Immutable to v5.0.0 as some downstream projects were having issues with DLL versioning and the System.Collections.Immutable DLL.

Added ability to specify custom keyComparer on V3 ConcurrentObservableDictionary

Added ability to specify custom keyComparer on V3 ConcurrentObservableDictionary

Fixed Reset in ConcurrentObservableSortedCollection

Fixed Reset in ConcurrentObservableSortedCollection, items weren't being sorted when added to the collection. See issue #17.