pipx install pkg1 pkg2 doesn't install pkg2 if pkg1 already installed #1509
Description
Describe the bug
If I have already installed black by running pipx install black and I attempt to run pipx install black isort, black is detected as having been already installed, and isort is not installed.
How to reproduce
pipx install black
pipx install black isort
# isort not installed!
Expected behavior
black should be detected as already installed, and isort should be installed by pipx
### Tasks
- [ ] https://github.com/pypa/pipx/pull/1510