An upstream update `impacket` pip package started requiring `blinker`.
An older version is shipping with Ubuntu, causing this on install:
```
Attempting uninstall: blinker
Found existing installation: blinker 1.7.0
ERROR: Cannot uninstall blinker 1.7.0, RECORD file not found. Hint: The package was installed by debian.
```
Fix it by switching to venv and install everything separate from the
system.
The overhead is the same as using `pip --ignore-installed`, which also
installs everything from scratch.
The 3rd option is to uninstall the system `python3-blinker` package, but
it was the slowest.
Closes#15578
2638570241