Fail to remove build-in bundle (to bypass infra issue)

On Windows 10, with Python 3.10.11, I try to use circup to migrate to CP 9.0.

To avoid errors, I wanted to remove a bundle, but I cannot remove it.

Not sure if that is normal.

```
C:\Project>python --version
Python 3.10.11

C:\Project>circup --version
CircUp, A CircuitPython module updater. Version 1.4.0

C:\Project>circup bundle-show
Downloading latest bundles for circuitpython/CircuitPython_Org_Bundle (20231029).
py:
There was a problem downloading that platform bundle. Skipping and using existing download if available.
adafruit/Adafruit_CircuitPython_Bundle
https://github.com/adafruit/Adafruit_CircuitPython_Bundle
version = 20231031
adafruit/CircuitPython_Community_Bundle
https://github.com/adafruit/CircuitPython_Community_Bundle
version = 20231030
circuitpython/CircuitPython_Org_Bundle
https://github.com/circuitpython/CircuitPython_Org_Bundle
version = 0.0.3

C:\Project>circup bundle-remove circuitpython/CircuitPython_Org_Bundle
Cannot remove built-in module:
circuitpython/CircuitPython_Org_Bundle
```

Start with the `bundle-remove` command and its handling of built-in bundles; reproduce the Windows and Python 3.10.11 commands shown in the report. Done means the expected behavior for removing `circuitpython/CircuitPython_Org_Bundle` is established and the command behaves accordingly.

Written by the indexing model from the issue text.