Migrate test discovery onto lwpt test

[frostney]

Summary

Run the *.Test.pas suite via lwpt test discovery.

Why

Consolidating test discovery and execution onto lwpt test completes the toolchain migration for the Pascal unit suite.

Current behavior

Pascal unit tests run via the project's own build/runner.

Expected behavior

• lwpt test discovers, compiles, and runs the *.Test.pas suite at parity.

Scope notes

• Part of the lwpt migration (parent Migrate toolchain to lwpt #826).