Bump file_selector and file_selector_web in /experimental/linting_tool (#1346)

Bumps [file_selector](https://github.com/flutter/plugins/tree/main/packages/file_selector) and [file_selector_web](https://github.com/flutter/plugins/tree/main/packages/file_selector). These dependencies needed to be updated together.

Updates `file_selector` from 0.8.2+1 to 0.9.0
- [Release notes](https://github.com/flutter/plugins/releases)
- [Commits](https://github.com/flutter/plugins/commits/file_selector-v0.9.0/packages/file_selector)

Updates `file_selector_web` from 0.8.1+5 to 0.9.0
- [Release notes](https://github.com/flutter/plugins/releases)
- [Commits](https://github.com/flutter/plugins/commits/file_selector_web-v0.9.0/packages/file_selector)

---
updated-dependencies:
- dependency-name: file_selector
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: file_selector_web
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

experimental/linting_tool/pubspec.yaml

@@ -14,10 +14,10 @@ dependencies:
   adaptive_breakpoints: ^0.1.1
   cupertino_icons: ^1.0.2
   equatable: ^2.0.3
-  file_selector: ^0.8.2
+  file_selector: ^0.9.0
   file_selector_linux: ^0.0.2+1
   file_selector_macos: ^0.9.0
-  file_selector_web: ^0.8.1+1
+  file_selector_web: ^0.9.0
   file_selector_windows: ^0.9.0
   flutter_markdown: ^0.6.2
   google_fonts: ^3.0.0