fix(docs): regenerate 6.1.0 snapshots with depth-aware import rewriter

The previous import-path fixer only matched two-level relative paths
(`../../src/` and `../../data/`), missing files at deeper nesting in the
section tree. After the 6.1.0 cut for developer_docs, ~50 component MDX
files at depth 3 still referenced `../../../src/components/StorybookWrapper`
(should have been `../../../../src/...`), and the components Button page
referenced `../../../superset-frontend/...` (should have been
`../../../../superset-frontend/...`). The Docusaurus production build
failed with module-not-found errors as a result.

Replace the pattern-specific regex with a depth-aware walker that
- counts the file's nesting depth within the snapshot,
- bumps any relative import whose `../` count exceeds that depth (i.e.
  the import escapes the section root and so must compensate for the
  extra `version-X.X.X/` directory the snapshot lives under),
- skips fenced code blocks so documented sample imports (e.g. Playwright
  page-object examples in developer_docs/testing/e2e-testing.md) are not
  rewritten.

Re-cut all four sections under the new fixer. yarn build now passes
locally.

docs/developer_docs_versioned_docs/version-6.1.0/components/ui/upload.mdx

@@ -22,7 +22,7 @@ sidebar_label: Upload
     under the License.
 -->
 
-import { StoryWithControls } from '../../../src/components/StorybookWrapper';
+import { StoryWithControls } from '../../../../src/components/StorybookWrapper';
 
 # Upload