Bumps [tar](https://github.com/isaacs/node-tar) and [npm](https://github.com/npm/cli). These dependencies needed to be updated together.

Updates `tar` from 7.5.16 to 7.5.19
- [Release notes](https://github.com/isaacs/node-tar/releases)
- [Changelog](https://github.com/isaacs/node-tar/blob/main/CHANGELOG.md)
- [Commits](isaacs/node-tar@v7.5.16...v7.5.19)

Updates `npm` from 11.17.0 to 11.18.0
- [Release notes](https://github.com/npm/cli/releases)
- [Changelog](https://github.com/npm/cli/blob/v11.18.0/CHANGELOG.md)
- [Commits](npm/cli@v11.17.0...v11.18.0)

---
updated-dependencies:
- dependency-name: tar
  dependency-version: 7.5.19
  dependency-type: indirect
- dependency-name: npm
  dependency-version: 11.18.0
  dependency-type: indirect
...

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

…lse (#4023)

A renderer extension named after a built-in token can return false to
fall back to the default renderer. The Parser decides that from a list
of built-in token type names, and 'checkbox' was never added to either
the block or the inline list when the checkbox token was introduced.

The result is that a `checkbox` renderer extension returning false
emits nothing instead of falling back, so the checkbox silently
disappears from the task item.

)

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

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

Bumps [undici](https://github.com/nodejs/undici) from 6.24.0 to 6.27.0.
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v6.24.0...v6.27.0)

---
updated-dependencies:
- dependency-name: undici
  dependency-version: 6.27.0
  dependency-type: indirect
...

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

## [18.0.8](v18.0.7...v18.0.8) (2026-08-04)

### Bug Fixes

* fall back to default checkbox renderer when extension returns false ([#4023](#4023)) ([e1b6139](e1b6139))

## [18.0.9](v18.0.8...v18.0.9) (2026-08-04)

### Bug Fixes

* an unmatched strong run before emphasis stays literal ([#4008](#4008)) ([e8544e6](e8544e6))
* Fix spurious deeper nesting in a blockquote continuation ([#4030](#4030)) ([452f1ed](452f1ed))
* pedantic **foo:** and **"word"** emphasis parsing ([#3999](#3999)) ([823093f](823093f))