Log Message:
devel/pkgconf: Update to 2.1.1

Changelog:
Changes from 2.1.0 to 2.1.1:
----------------------------

* Documentation fixes from Sam James and Stefan Weil.

* Fix --modversion with constraints.
  Patch by Kai Pastor.

* Reintroduce an optimization to the dependency graph walker which avoids
  revisiting already visited nodes.
  Patch by Yi Chou with some modifications.

* Add a regression test to check that the dependency flattener is working
  as expected.
  Patch by Kai Pastor.

Changes from 2.0.3 to 2.1.0:
----------------------------

* Do not flatten the solver solution into the original world used as
  input to the solver.
  Patches by Kai Pastor.

* Fix warnings with GCC 14 -Walloc-size.
  Patch by Sam James.

* Add --solution to the pkgconf CLI to dump the solver state.

* Improve the --digraph output to clarify cancelled edges in a given
  solution.

* Demote requires dependencies to requires.private when a parent
  dependency is pulled in via requires.private.

* Trim trailing whitespace when processing package arguments.
  Patch by Colin Gillespie.

* Avoid strncmp() in --modversion version comparison.
  Patch by Colin Gillespie.

* Update autoconf compile flag checking macro.
  Patch by Peter Kokot.

* Add system default path configuration to Meson.
  Patch by L. E. Segovia.

* Fix order of PKG_CONFIG_LIBDIR and PKG_CONFIG_PATH element processing.