## Why
Made a mistake when carving #29746 out of my local changes and the test
was missing from the build graph. Oops!
## What
Enable the app-server Wine exec test target. Remove the `manual` tag
from generated Wine-exec test variants so wildcard Bazel test
invocations select them. Refactor the smoke test to ensure it passes
with current Windows support.
## Why
Start moving towards app-server tests defaulting to running against
remote & foreign OS executors. To do so we need a point of indirection
similar to core integration tests' `build_with_auto_env`, but with the
flexibility of letting tests control environment registration if they
need to.
## What
This adds:
- `TestAppServer::new_with_auto_env()` for constructing an app server
with a default environment defined by the test runner (e.g. bazel)
- `TestAppServer::auto_env_params()` for tests to easily acquire turn
env params tailored to the automatic environment
- `TestAppServer::send_thread_start_request_with_auto_env()` to make it
easy for tests to start a thread using the automatic environment
The above methods all fail if the test calling them has set up an
environment where the automatic environment configuration conflicts with
test-created state.
## Validation
Adds a couple of basic smoke tests to the app-server test suite.
Follow-ups will migrate more tests to use it.