astrocommunity.pack.cs-omnisharp lsp not working

The omnisharp lsp is not working on neovim 0.11.4

# neovim
```
NVIM v0.11.4
Build type: RelWithDebInfo
LuaJIT 2.1.1753364724
Run "nvim -V1 -v" for more info
```
# dotnet
```
.NET SDK:
Version: 9.0.110
Commit: 999243871a
Workload version: 9.0.100-manifests.3277c30b
MSBuild version: 17.12.44+999243871

Runtime Environment:
OS Name: arch
OS Version:
OS Platform: Linux
RID: arch-x64
Base Path: /usr/share/dotnet/sdk/9.0.110/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
Version: 9.0.8
Architecture: x64
Commit: a1e39f97e5

.NET SDKs installed:
9.0.110 [/usr/share/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.8 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.9 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
None

Environment variables:
Not set

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download

```

Start with the astrocommunity.pack.cs-omnisharp specification and reproduce the failure on Neovim 0.11.4 using the reported .NET 9.0.110 environment. Inspect the attached failure report and LSP startup behavior; done means OmniSharp works in the reported setup.

Written by the indexing model from the issue text.