chore: add missing transitive dependencies

Add dependencies that were only available transitively through other
packages but were being imported directly:

- csstype and copy-to-clipboard in @backstage/core-components
- @storybook/react-vite in @backstage/ui
- react-aria-components in @backstage/plugin-notifications
- @octokit/core in @backstage/plugin-scaffolder-backend-module-github
- @rjsf/utils in example-app-legacy

Signed-off-by: Fredrik Adelöw <freben@spotify.com>
Made-with: Cursor

.changeset/add-missing-transitive-deps.md

@@ -0,0 +1,8 @@
+---
+'@backstage/core-components': patch
+'@backstage/ui': patch
+'@backstage/plugin-notifications': patch
+'@backstage/plugin-scaffolder-backend-module-github': patch
+---
+
+Added missing dependencies that were previously only available transitively.