CopyQ Freezes When Accessing Own Clipboard Data in Wayland

## Describe the bug
When using CopyQ in Wayland (without XWayland), the application freezes for about 1 second when attempting to paste an item immediately after selecting it in the CopyQ interface. This issue appears to be related to two recent commits related to accessing the clipboard in Wayland: `c55fcb2c` (Wayland: Fix accessing own clipboard) and `bfe76c16` (Wayland: Fix crash when getting own clipboard data).

## To Reproduce
1. Run CopyQ server
2. Copy some text to clipboard from any application
3. Paste the text anywhere - this works fine, no delay
4. Run `copyq show` to open the GUI
5. Select the first item (the one just copied)
6. Immediately attempt to paste it (within 1 second) - CopyQ freezes for about 1 second
7. If you wait longer than 1 second after selecting the item before pasting, no freeze occurs

## Expected behavior
Selecting an item from CopyQ and immediately pasting it should work without any delay or freeze.

## Version, OS and Environment
- CopyQ master branch (latest commit before bisect)
- OS: Debian GNU/Linux 13 (trixie) x86_64
- Kernel: Linux 6.12.38+deb13-amd64
- WM: Sway 1.10.1 (Wayland)
- Pure Wayland environment (XWayland disabled)

## Additional context
Bisecting the issue identified two problematic commits:
- `c55fcb2c` (Wayland: Fix accessing own clipboard)
- `bfe76c16` (Wayland: Fix crash when getting own clipboard data)

Reverting these commits fixes the issue completely - selecting and pasting works fluently with no warnings or freezes.

During the freeze, the following warnings appear in the log:
```
Warning: [default] QtWarning: DataControlOffer: timeout reading from pipe
Warning: ELAPSED 1010 ms accessing [data:text/plain]
Warning: ELAPSED 1012 ms accessing [UTF8:text/plain]
Warning: [default] QtWarning: DataControlOffer: timeout reading from pipe
Warning: ELAPSED 1011 ms accessing [:imageData]
```