[infra] Enable skipping tests via environment variables #137
Description
We should add some logic to our test suites so that we can invoke them to only run all tests targeting a specific architecture/os.
Use cases:
- Locally running tests if not all tooling is installed.
- Running extra CI jobs targeting different compilers, and not having to install the compilers for all the other architectures/oses. [CI] Clang 17 (from Dart SDK) CI coverage #135