deps(dev): bump the major-dependencies group across 1 directory with …

…3 updates

Bumps the major-dependencies group with 3 updates in the / directory: [@astrojs/tailwind](https://github.com/withastro/astro/tree/HEAD/packages/integrations/tailwind), [tailwind-merge](https://github.com/dcastil/tailwind-merge) and [tailwindcss](https://github.com/tailwindlabs/tailwindcss/tree/HEAD/packages/tailwindcss).


Updates `@astrojs/tailwind` from 5.1.4 to 6.0.0
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/integrations/tailwind/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/@astrojs/[email protected]/packages/integrations/tailwind)

Updates `tailwind-merge` from 2.6.0 to 3.0.1
- [Release notes](https://github.com/dcastil/tailwind-merge/releases)
- [Commits](dcastil/tailwind-merge@v2.6.0...v3.0.1)

Updates `tailwindcss` from 3.4.17 to 4.0.3
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/tailwindlabs/tailwindcss/commits/v4.0.3/packages/tailwindcss)

---
updated-dependencies:
- dependency-name: "@astrojs/tailwind"
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: major-dependencies
- dependency-name: tailwind-merge
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: major-dependencies
- dependency-name: tailwindcss
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: major-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>