available in a package.  However, not all licenses are compliant with
each other. A chart indicating which licenses can be included with other
licenses is available at:
https://dwheeler.com/essays/floss-license-slide.html
Would it be possible to create a similar chart for all SPDX identifiers
that can be used in Fedora?  This would enable adding such a check to
fedora-review.

IANAL but this can be hardly applied to package. This graph can be applied on the same or derived work. But not on the collection of work. Which package is.

E.g., I can have a package which contains tools:

 /usr/bin/foo

 /usr/bin/bar

foo is licensed as LGPLv2.1 and bar is licensed as MPL 1.1. Although these two licenses are not compatible, I see no problem to have these two separate tools in the same package. And package to have license  LGPL-2.1-or-later AND MPL 1.1 (or what is the SPDX id).

Miroslav