Bumps [extensions/PDFEmbed](https://github.com/miraheze/PDFEmbed) from `5c1efbf` to `22ea240`.
- [Release notes](https://github.com/miraheze/PDFEmbed/releases)
- [Commits](miraheze/PDFEmbed@5c1efbf...22ea240)

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