Fix finding utbot-instrumentation-shadow.jar

[IlyaMuravjov]

Description

Fixes #2277

How to test

Manual tests

1. Install UnitTestBot plugin built from this branch in IntelliJ IDEA Ultimate 2023.1
2. Open/clone UTBotJava project
3. Generate tests for a sample - f.i. algorithms/Sort.java or stream/BaseStreamExample.java with default settings

Self-check list

• I've set the proper labels for my PR (at least, for category and component).
• PR title and description are clear and intelligible.
• I've added enough comments to my code, particularly in hard-to-understand areas.
• The functionality I've repaired, changed or added is covered with automated tests.
• Manual tests have been provided optionally.
• The documentation for the functionality I've been working on is up-to-date.

[EgorkaKulikov]

@tyuldashev has checked that the mentioned issue is fixed.