…pace is not available (#25780)

…client and server (#25774)

…scripts (#25864)

…ndows (#25847)

Implementation for PowerShell/PowerShell-RFC#391. A few implementation decisions:

1. Check the package manager list only once per process (**same as CMD**). So, changing the package manager list in registry doesn't affect a PowerShell session that is already running.

2. When detecting user/system PATH value changes, only check new items PREPENDED or APPENDED to the original string (**same as CMD**). The detection is made simple, which is not intended to detect complex changes to the user/system PATH.

3. The PATH update feature is disabled when the `Environment` provider is not available, or when the current session is restricted.
    - Both `Environment` provider and `IsSessionRestricted` are checked only once per PowerShell session.
    - Use `ConditionalWeakTable` to cache whether the feature is enabled or not for a given session.
    - We cannot use `thread-static` variable for the caching because it's possible for Runspace to reuse threads.

Co-authored-by: Travis Plunk (HE/HIM) <tplunk@ntdev.microsoft.com>
Co-authored-by: Travis Plunk <travis.plunk@microsoft.com>

…5849)

Co-authored-by: Patrick Meinecke <SeeminglyScience@users.noreply.github.com>

…5910)

#26474)

…r in the middle of a string (#26424)

…s patterns (#26483)

)

…lass (#26574)

…#26602)

This fixes test isolation issues where six test files were leaking $PSDefaultParameterValues["It:Skip"] settings to subsequent tests, causing widespread test skipping on Linux. The fixes address two distinct patterns: using .Remove() which doesn't restore the original state (4 files), and imbalanced Push-DefaultParameterValueStack/Pop-DefaultParameterValueStack calls (2 files).

… easier to maintain (#26565)

)

…ly (#26610)

…in `BeforeAll` failed (#26621)

…ma (#26618)

1. Fix the conditions used in `release-MSIX-Publish.yml`
2. Update `build.psm1` to not install dotnet format tool for ADO build.