Mark deprecated packages

Description

• Some packages are designed as workaround for compiler bugs or limitation, e.g:

  • https://typst.app/universe/package/indenta: for https://github.com/typst/typst/issues/311
  • https://typst.app/universe/package/natrix: for https://github.com/typst/typst/issues/1617

  When the compiler fixes the related bugs, these packages shall not be used anymore.

• Some old packages may be not actively maintained and can be replaced by some other better and actively maintained packages. The old package owners can mark them deprecated.

• ...

It would be nice to notify the users to remove the deprecated dependencies, especially when the users update their typst compiler and try to use it to compile an existing document.

Maybe we can allow package authors and typst maintainers to add some metadata (e.g. deprecated-since: '0.12.0') for a package at preview/{package}/meta.toml. More metadata can be added in it, so this design is not limited to deprecate a package.

By this design, the compiler can check this metadata and issue warnings to users.

Start by inspecting the package metadata at preview/{package}/meta.toml and how the Typst compiler currently handles package metadata. Determine how a deprecation field should be represented and when users should receive warnings. Done means the metadata design and compiler warning behavior are defined and validated for the described package cases.