Log Message:
pkgconf: updated to 2.4.0

Changes from 2.3.0 to 2.4.0:

* Allow multiple package names in solution-based queries such as
  `--print-requires`, `--print-requires-private` and `--print-provides`.

* Use `_DEFAULT_SOURCE` where appropriate on Meson.

* Add an abstract buffer type and use it when loading files from disk
  instead of a 64KB buffer.  This ensures large pkg-config files are
  not truncated.

* Disable graph recursion in `--variable` queries as it was generating
  duplicate output.

* Add infrastructure for tracking fragment group relations and convert
  storage of fragments to use a tree-like structure instead of string
  concatenation.

* Add support for tracking linker groups, e.g.

    -Wl,--start-group -la -lb -lc -Wl,--end-group

  as fragment groups.

* Properly contextualize the sysroot directory when processing package
  information, ensuring packages where ${pc_sysrootdir} does not match
  the default are properly processed.