[LOW] Bump @babel/core to 7.29.7

[OskarEichler]

Summary:

Bumps @babel/core from the vulnerable 7.28.0 lockfile resolution to 7.29.7, resolving GHSA-4x5r-pxfx-6jf8 / CVE-2026-49356. The reviewed advisory allows malicious source code compiled by Babel to read a known local source-map path when the attacker can observe the generated output.

All compatible workspace and transitive ranges are consolidated on 7.29.7. The Babel preset fixture is regenerated to capture the updated async-generator helper emitted by the patched Babel toolchain.

Changelog:

[INTERNAL] [SECURITY] - Update @babel/core to a release that prevents source-map path file reads from crafted input.

Test Plan:

• yarn install --frozen-lockfile --ignore-scripts
• yarn why @babel/core confirms compatible consumers resolve to 7.29.7
• yarn audit --groups dependencies no longer reports GHSA-4x5r-pxfx-6jf8
• yarn build
• Focused Babel, transformer, and codegen Jest suites:
  • 72 suites passed
  • 3,285 tests passed
  • 1,309 snapshots passed
• git diff --check