Plugin issues with Git worktrees

I would like to use Git worktrees to work on two tasks in parallel (e.g. one worktree for my primary work, second worktree for emergency fixes). Unfortunately there are a couple of issues with Axion Release Plugin, when working in this way:

1. in the second worktree, the plugin does not recognize that it is in a Git repository. It looks like it only checks for the presence of `.git` directory, but it is insufficient. It should also check registered worktrees.
2. once it does not find `.git` directory, it tries to check other options and it crashes upon encountering `config` directory (it expects the file)

Point 2 is also not valid. If the plugin notices `config` directory while expecting a file, it should silently skip it instead of crashing. Many tools use `config` directory (Checkstyle, PMD to mention some) and in my case, they auto-generate the basic configuration every time I launch Gradle, and I need to remove this directory manually over and over again just to make it work.

Example output:

```
Build file '/path/to/my/project/build.gradle.kts' line: 87

java.io.FileNotFoundException: /path/to/my/project/config (Is a directory)
> /path/to/my/project/config (Is a directory)

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
```