Remove Babel from stackgl_modules build process

[coyaSONG]

Summary

• remove the babel-loader rules and the explicit ES5 webpack target from the stackgl_modules build
• remove the four Babel build dependencies and prune their transitive lockfile entries
• regenerate the tracked stackgl bundle with the repository's Node 18 / npm 10 toolchain

Closes #7862.

Impact

The stackgl vendor build now relies on webpack directly while keeping the existing ify-loader and raw-loader rules. The generated bundle continues to render representative scatter3d, mesh3d, and surface figures identically to the unmodified base build.

Dependabot PR #7903 updates @babel/core, which this change removes, so this PR supersedes that dependency update if merged.

Validation

• npm run bundle-stackgl (Node 18.20.8 / npm 10.9.4)
• npm run cibuild (Node 18.20.8 / npm 10.9.4)
• npm run test-jasmine -- scatter3d mesh3d surface --nowatch --report-dots (61/61 passed)
• npm run lint
• npm run test-mock -- gl3d_scatter3d-colorscale-with-line gl3d_mesh3d_coloring gl3d_surface_intensity
• rendered the same three mocks from this branch and the unmodified base with Kaleido 1.2 / Plotly 6.6.0; all three PNG outputs were byte-identical
• audited the lockfile delta: 143 packages removed, 0 added, 0 retained package version/integrity changes, and every removal is reachable from the removed Babel toolchain

Submission checks

• based on the latest master (437cb2be78d12bfd7d1bc8bb7527bd238471314b)
• no dist/ files committed
• stackgl_modules/package-lock.json updated
• maintainer edits allowed on the fork branch

AI assistance

OpenAI Codex (GPT-5) was used to investigate the issue, implement the scoped change, and run the checks listed above. The resulting diff and test outputs were inspected before submission.

[camdecoster]

Thanks for the PR! After some team discussions, I think we're going to handle this internally as there will be some architectural changes. I'm closing your PR since we'll create a new one. Thanks again!