Store the TaskfileGraph in the Executor so it can be used for lazy
variable resolution when SCOPED_INCLUDES experiment is enabled.
The graph is now preserved after reading, before merging into the
final Taskfile. This allows traversing the DAG at runtime to resolve
variables from the correct scope.
* docs: Update Remote Taskfiles default values
This change updates the documentation for [Remote Taskfiles > Configuration](https://taskfile.dev/docs/experiments/remote-taskfiles#configuration) for `timeout` and `cache-expiry` to match the defaults in code.
* docs: Update `cache-expiry` default to 0s
* docs: Update executor.go comment
Fix doc comment to indicate that cache expiry default duration is 0.
* feat: use TaskTest for executor tests
* feat: more tests
* feat: separate tests for executing and formatting with new functional options that work for both test types
* feat: formatter tests
* refactor: more tests
* refactor: executor functional options
* refactor: minor tidy up of list code
* fix: WithVersionCheck missing from call to NewExecutor
* feat: docstrings for structs with functional options
* refactor: prefix the functional options with the name of the struct they belong to
