The dependency check currently checks whether there are only build
dependencies left for a particular package. However, the database also
contains uninstalled packages, which can cause the check to fail.
For instance, with `bison` and `flex` having already been uninstalled,
`m4` will have the following dependents:
```
bison ('build', 'run')--> m4
flex ('build',)--> m4
libnl ('build',)--> m4
```
`bison` and `flex` should be ignored in this case because they are not
installed anymore.
Fixes#30673
ff03e2ef4c