Another 7.4 breaking change with Test-Json - JSON with comments (#11244)

* Added info about another breaking change with Test-Json

* Added info about another breaking change with Test-Json

* Update What-s-New-in-PowerShell-74.md

Editorial changes

---------

Co-authored-by: Sean Wheeler <sean.wheeler@microsoft.com>

reference/docs-conceptual/whats-new/What-s-New-in-PowerShell-74.md

@@ -18,9 +18,12 @@ For a complete list of changes, see the [CHANGELOG][chg] in the GitHub repositor
 - Update some PowerShell APIs to throw **ArgumentException** instead of **ArgumentNullException**
   when the argument is an empty string ([#19215][19215]) (Thanks @xtqqczze!)
 - Remove code related to `#requires -pssnapin` ([#19320][19320])
-- `Test-Json` now uses JsonSchema.Net instead of Newtonsoft.Json.Schema. With this change,
-  `Test-Json` no longer supports the older Draft 4 schemas. ([#18141][18141]) (Thanks @gregsdennis!)
-  For more information about JSON schemas, see [JSON Schema][14] documentation.
+- `Test-Json` now uses JsonSchema.NET instead of Newtonsoft.Json.Schema.
+  - With this change, `Test-Json` no longer supports the older Draft 4 schemas. ([#18141][18141])
+    (Thanks @gregsdennis!). For more information about JSON schemas, see [JSON Schema][14]
+    documentation. This also breaks `Test-Json` for JSON and JSONC files with comments.
+  - `ConvertFrom-Json` support still uses Newtonsoft.Json.Schema so it can convert JSON files
+    with comments.
 - Output from `Test-Connection` now includes more detailed information about TCP connection tests
 - .NET introduced changes that affected `Test-Connection`. The cmdlet now returns an error about
   the need to use `sudo` on Linux platforms when using a custom buffer size ([#20369][20369])
@@ -264,7 +267,6 @@ For more information about the Experimental Features, see [Using Experimental Fe
 [18653]: https://github.com/PowerShell/PowerShell/pull/18653
 [18682]: https://github.com/PowerShell/PowerShell/pull/18682
 [18691]: https://github.com/PowerShell/PowerShell/pull/18691
-[18695]: https://github.com/PowerShell/PowerShell/pull/18695
 [18717]: https://github.com/PowerShell/PowerShell/pull/18717
 [18726]: https://github.com/PowerShell/PowerShell/pull/18726
 [18731]: https://github.com/PowerShell/PowerShell/pull/18731