Running "dart analyze" on a monorepo doesn't work with ignored files

[johnpryan]

dart analyze doesn't respect files in the exclude section of a sub-package's analysis_options.yaml file

Steps to reproduce

1. Clone github.com/dart-lang/dart-pad
2. Run pub get for each package in the pkgs/ directory
3. From the root directory, run dart analyze.
4. Observe that analysis errors are reported for files that are listed in the exclude section of pkgs/dart_pad/analysis_options.yaml, such as build/. Running dart analyze from pkgs/dart_pad completes with no issues.

[srawlins]

Possible dupes / root causes: #52283, #28463, #26752

Related: #41582