notebook cell language is not updated

[brettfo]

• VSCode Version: 1.49.0-insider, commit e790b93
• OS Version: Win10 19041.450 (2004)

Steps to Reproduce:

1. Install the .NET Interactive Notebook Extension to the latest insiders build.
2. Open a blank .dib file.
3. The first cell is C#.
4. Execute the code ls.
5. It fails as expected.
6. Change the cell language to PowerShell.
7. Re-execute the cell.
8. The cell's language is still reported as C# as confirmed by a breakpoint here.

Does this issue occur when all extensions are disabled?: N/A

Issue first discovered in dotnet/interactive#764.

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Creating a new notebook cell copies time metadata over. (#100339)

[rebornix]

Fixed via c53524a

[connor4312]

I was not able to verify this -- either opening a blank .dib file or creating a new one via the .NET Interactive: Create new blank notebook command resulted in an infinitely loading notebook on the latest insiders

[rzhao271]

Adding author-verification-requested because I got the same result as @connor4312 and I'm not sure whether that means something regressed.

[github-actions]

Unable to locate closing commit in issue timeline. You can manually reference a commit by commenting \closedWith someCommitSha.