[IMPROVEMENT] Do not show WinGet updates that WinGet itself cannot install (example: MSYS2) #5597

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• I have searched for my feature proposal and have not found a work-in-progress/duplicate/resolved/discarded issue.
• This improvement refers to an existing feature. If you want to suggest a new feature, please use this template.
• This improvement is not a bug. If you want to report a bug, please use this template.

Describe the improvement

Summary

UniGetUI shows an update for MSYS2. The update always fails.
WinGet marks this package as "explicit upgrade only". UniGetUI does not use this mark.

What happens

1. UniGetUI shows "MSYS2 Installer 20260611 -> 20260927" in Software Updates.
2. I start the update. WinGet stops with this message:
   "The package cannot be upgraded using WinGet. Please use the method
   provided by the publisher for upgrading this package." (0x8A150114)
3. I change the scope to "user" and set the install location. The update fails again.

MSYS2 updates itself with its own package manager (pacman).
WinGet cannot install this update. It does not matter which options I set.

What WinGet does

WinGet knows about this. The command winget upgrade does not show MSYS2
in the list of normal updates. WinGet shows MSYS2 in a separate list:
"The following packages have an upgrade available, but require explicit
targeting for upgrade."

What I expect

UniGetUI does the same as WinGet:

• UniGetUI does not show these packages as normal updates.
• Or: UniGetUI shows them with a clear note, for example
  "This package updates itself".
• If WinGet returns 0x8A150114, UniGetUI tells the user why the update failed.
  UniGetUI then offers "Ignore updates for this package".

Workaround

I ignore updates for this package manually.

Where this happens in the code (current main)

• NativeWinGetHelper.GetAvailableUpdates_UnSafe() adds each package that has
  IsUpdateAvailable = true. It does not check for "explicit upgrade only".
• WinGetCliHelper.ParseAvailableUpdates() reads all tables from
  winget update. It also reads the "require explicit targeting" table
  as normal updates.
• WinGetPkgOperationHelper handles the error code 0x8A150014.
  It does not handle 0x8A150114.

Related issues: #882 (explicit-targeting table), #2296 (same problem with Miniconda).

Environment

• UniGetUI 2026.3.2
• WinGet v1.29.380
• Windows 11 Pro, build 26300
• MSYS2 installed for the current user only

Describe how this improvement could help users

Users see an update that can never succeed. They try it, it fails, and they
do not know why. Then they try other options and it fails again.

With this improvement, UniGetUI shows only updates that WinGet can install.
For packages that update themselves (MSYS2, Miniconda, and others), users
get a clear note and know which tool to use. This saves time and avoids
confusing error messages.