Parent pom (in multi-module project) permanently cached after first build

### Affected version

1.0.3

### Bug description

In a **multi-module** project, e.g.
```
├── module-1
│   ├── src
│   └── pom.xml
├──module-2
│   ├── src
│   └── pom.xml
└── pom.xml
```
after the first (per `mvnd` instance) build is run (from the root of the project), e.g.
```
mvnd package
```
the (multi-module) parent pom seems to be persistently cached by `mvnd`. Changes to the parent pom are simply ignored until the `mvnd` is restarted.

Be it
```
mvnd package
```
or even
```
mvnd clean package
```
will re-use the parent pom that was initially loaded.

If any of the modules pom files are changed though, that is picked up by `mvnd`. But the project parent pom seems to never be refreshed/reloaded. Doing
```
mvnd --stop
```
followed by
```
mvnd package
```
will pick up the changed parent pom.

In a non multi-module project no such issue occurs.

If I use `mvn` I have no such issue.

My `mvnd` command is aliased to this (not sure if relevant):
```
mvnd -ntp \
-s path/to/maven/settings.xml \
-Dmaven.repo.local=path/to/local/repo \
-Daether.dependencyCollector.impl=bf
```

Start with the multi-module layout and root pom.xml described in the report, then reproduce the issue by running mvnd package, changing the parent POM, and running it again. Compare this with mvnd --stop followed by mvnd package and with a non-multi-module project. Done means parent POM changes are detected without restarting mvnd, including after mvnd clean package.

Written by the indexing model from the issue text.