build_runner test vm integration test failing on windows with github actions

[jakemac53]

In the _test directory, the command dart run build_runner test -- -p vm test/configurable_uri_test.dart is failing on github windows CI. The failure looks like this:

Failed to load "test/configurable_uri_test.dart":
  Unable to spawn isolate: Crash when compiling file:///D:/C:/Users/RUNNER~1/AppData/Local/Temp/build_runner_testc8873[38](https://github.com/dart-lang/build/actions/runs/3677992076/jobs/6220731377#step:6:39)9/test/configurable_uri_test.dart.vm_test.dart:
  Unsupported operation: Illegal character in path: C:

Looks related to multiple drives and paths. For now the test is just disabled for windows in the mono_repo.yaml

[jakemac53]

There are also some similar tests in _test_null_safety that are failing (and now disabled)