PSModulePath mutated during script changes

[TylerLeonhardt]

Issue Description

PSModulePath is modified with every edit to a file.

Steps to repo

Run this in the PSIC:

$env:PSModulePath
$env:PSModulePath = "C:\Users\tyleonha\.vscode-insiders\extensions\ms-vscode.powershell-preview-2019.5.0\modules"
$env:PSModulePath

Verify it changed.

Now make a single edit to a script and check the PSModulePath once more... It should look like:

C:\Users\tyleonha\Documents\PowerShell\Modules;C:\Users\tyleonha.vscode-insiders\extensions\ms-vscode.powershell-preview-2019.5.0\modules;C:\Program Files\PowerShell\Modules;c:\program files\powershell\7-preview\Modules;C:\Windows\system32\WindowsPowerShell\v1.0\Modules

Apparently, the PSModulePath is updated every time you spin up a Runspace so I wonder if we're doing something like that...

Attached Logs

Follow the instructions in the README about
capturing and sending logs.

Environment Information

Visual Studio Code

Name	Version
Operating System	Windows_NT x64 10.0.18362
VSCode	1.35.0-insider
PowerShell Extension Version	2019.5.0

PowerShell Information

Name	Value
PSVersion	7.0.0-preview.1
PSEdition	Core
GitCommitId	7.0.0-preview.1
OS	Microsoft Windows 10.0.18362
Platform	Win32NT
PSCompatibleVersions	1.0 2.0 3.0 4.0 5.0 5.1.10032.0 6.0.0 7.0.0-preview.1
PSRemotingProtocolVersion	2.3
SerializationVersion	1.1.0.1
WSManStackVersion	3.0

Visual Studio Code Extensions

Visual Studio Code Extensions(Click to Expand)

Extension	Author	Version
azure-account	ms-vscode	0.8.4
csharp	ms-vscode	1.19.1
horizon-theme-vscode	jolaleye	1.8.1
powershell-preview	ms-vscode	2019.5.0
remote-containers	ms-vscode-remote	0.57.0
remote-ssh	ms-vscode-remote	0.41.0
remote-ssh-edit	ms-vscode-remote	0.41.0
remote-ssh-explorer	ms-vscode-remote	0.41.0
remote-wsl	ms-vscode-remote	0.36.0
vscode-azurefunctions	ms-azuretools	0.17.1
vscode-remote-extensionpack	ms-vscode-remote	0.14.0