Vendored dependencies aren't used when running tests.

[Mark-Boger]

Describe the bug
When using dependencies vendored with :mvn/local-repo running poly test will re-download the dependencies in the directory specified by :m2-dir. It seems that the only place to configure :m2-dir is in ~/.config/polylith/config.edn.

To Reproduce
Steps to reproduce the behavior:

1. Create a new project and create a deps.edn with :mvn/local-repo
2. Download dependencies
3. Remove internet access
4. Run poly test

Expected behavior
Polylith uses dependencies from the directory specified by :mvn/local-repo

Operating System (please complete the following information):

• OS: Linux
• Version: alpine-minirootfs-3.21.2-x86_64
• OS: MacOS
• Version: 15.3

Versions (please complete the following information):

• Java: jdk-17.0.14+7
• Poly: 0.2.21 (2024-08-10)

Additional context
Our pipeline runs in a restricted environment and cannot fetch dependencies from Clojars directly. Running poly test attempts to download the dependencies and causes the pipeline to fail.

Creating a ~/.config/polylith/config.edn with an :m2-dir pointing to the vendored dependencies during pipeline setup has not worked for some reason and we're still investigating the cause.

[tengstrand]

@Mark-Boger Please verify the branch issue-532, the latest commit e708d7a.

[tengstrand]

This is merged to master (0.2.22-SNAPSHOT 10) and cljs-support now.