chore: Bump vega-embed==7

[franzhaas]

Thanks for contributing to Altair! 🎉

Please follow these guidelines:

1. PR Description

• bump version of vega embed, as it fixes my issue with tooltips on nbconvert --to slides

2. Tests & Docs

• no additonal tests

3. Commit Message

• Use semantic commit messages, e.g., "feat: Add embed_options to charts".
• Add ! for breaking changes (e.g., "fix!: Raise error when embed_options is None").

4. PR Title Types

• feat: New feature
• fix: Bug fix
• docs: Documentation changes
• style: Code style changes (no functionality change)
• refactor: Code restructuring
• perf: Performance improvements
• test: Add or fix tests
• build: Changes to build system or dependencies
• ci: CI configuration changes
• chore: Miscellaneous tasks
• revert: Reverts a commit

[franzhaas]

as discussed here.: #3828

[mattijn]

Thanks for this PR, it looks great. You had to bump the version at a few places I see. Something we should be aware of when updating to vegalite 6. Thanks again!

[franzhaas]

Thanks!

[franzhaas]

Thanks for this PR, it looks great. You had to bump the version at a few places I see. Something we should be aware of when updating to vegalite 6. Thanks again!

If you want I can provide a PR for that as well...

[mattijn]

It is a bit more work, but if you are able to, that would be great😊, there are docs here, https://github.com/vega/altair/blob/main/NOTES_FOR_MAINTAINERS.md, that describe this process, but please report anything that is unclear in the process, which can be used to improve the notes.