This is a phase 1 change to the installers behavior to fix existing issues

• Removed unnecessary elevation check in GetRevitAddonsFilePath method.
• Updated unit tests to verify behavior of GetRevitAddonsFilePath with allusers parameter for different Revit versions.
• Ensured paths are correctly returned based on user and allusers settings.

fixes: #2611

1.1 – GetRevitAddonsFilePath (RevitAddons.cs)

• Removed the elevation block that forced allusers = true when running elevated.
• Removed the unused rootFolder variable.
• Kept the single return that uses GetRevitAddonsFolder(revitYear, allUsers: allusers).
  GetRevitAddonsFilePath now only uses the allusers parameter; elevation no longer overrides it.

1.2 – Admin installer (pyrevit-admin.iss)

• In the [Run] step “Attaching this clone…”, parameters changed from
  "attach master default --installed"
  to
  "attach master default --installed --allusers".

1.3 – Per-user installer (pyrevit.iss)

• Confirmed the attach [Run] line is
  Parameters: "attach master default --installed"
  (no --allusers). No change made.
  1.5 – Unit tests (pyRevitLabs.UnitTests.RevitAddons.cs)

• Existing tests already use allusers: false and do not rely on elevation overriding allusers; no changes needed there.

• Added GetRevitAddonsFilePath_ExplicitAllUsers_Test:

  • allusers: false → path contains AppData or Roaming.
    - allusers: true for 2026 → path under CommonApplicationData.
  • allusers: true for 2027 → path contains Addins and 2027 and ends with TestAddin.addin.

Verification

• Build: dotnet build pyRevitLabs.sln -c Release completed successfully (0 errors; existing SYSLIB0014 warnings only).
• Tests: Unit test run finished with exit code 0.

Behavior

• Per-user installer (even when run elevated): .addin goes to user scope: %AppData%\...\Revit\Addins\<YEAR>\
• Admin installer: .addin goes to all-users scope (ProgramData for Revit ≤2026, Revit install path for 2027+), because the post-install step uses --allusers