Extension may keep .csproj files open preventing Visual Studio from running them

Side note: I have no CSharp: Report an issue (not present in preview?)

## Environment data
`dotnet --info` output:

.NET SDK:
Version: 7.0.302
Commit: 990cf98a27

Runtime Environment:
OS Name: Windows
OS Version: 10.0.19045
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\7.0.302\

Host:
Version: 7.0.5
Architecture: x64
Commit: 8042d61b17

.NET SDKs installed:
7.0.302 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.16 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

global.json file:
Not found

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

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

VS Code version:

[Window Title]
Visual Studio Code

[Main Instruction]
Version: 1.78.2 (user setup)
Commit: b3e4e68a0bc097f0ae7907b217c1119af9e03435
Date: 2023-05-10T14:39:26.248Z (4 wks ago)
Electron: 22.5.2
Chromium: 108.0.5359.215
Node.js: 16.17.1
V8: 10.8.168.25-electron.0
OS: Windows_NT x64 10.0.19045
Sandboxed: Yes

C# Extension version:

C#
v2.0.206
Pre-Release

## OmniSharp log

N/A

## Steps to reproduce

Not consistent. I was not actively using the extension but it was running in the background with the solution open.

## Expected behavior

Visual Studio should be able to continue using the same solution/project files without interference even if VS Code has them open.

## Actual behavior

Occasionally Visual Studio will display an error indicating a CSPROJ file is locked. This may happen when using the "Start" button to run a project.

## Additional context

Upon closing the VS Code window for the project the file was no longer locked. Reopening the window could not reproduce the issue. Possibly the extension is leaking a file handle somewhere?