Test terminal.integrated.inheritEnv

[Tyriar]

Test for #70248

• Mac @kieferrm
• Linux over Remove-SSH @kieferrm
• Linux @rebornix

Complexity: 3

There is a new setting terminal.integrated.inheritEnv which when set to false will not use inherit window's environment, instead:

• On Linux it will get the parent of the main process and fetch its environment via procfs
• On macOS it will create a new environment taking only a few keys from the current environment
• On Windows nothing (deferred in another issue)

This was added such that the integrated terminal would work more like a regular terminal and not jumble $PATH up by running the profile/rc scripts several times. Things to verify:

• $SHLVL (shell level) should be 1
• The environment in the integrated terminal should be the same as an external terminal (provided it's launched as the same login/non-login shell). Note that on macOS it may differ a little due to the approach taken, a better fix will need a native node module (When terminal.integrated.inheritEnv is false on macOS, the env should be fetched via a native node module #76052).

Some more context: #70248, #75376,

[rebornix]

@Tyriar if I understand correctly, I should not expect the same result for echo $PATH when using SSH extension, right?

[kieferrm]

This works as expected locally on macOS. Issues on Linux remote. See microsoft/vscode-remote-release#823.

[Tyriar]

@rebornix see microsoft/vscode-remote-release#823 for remote