gnu: farstream: Disable a failing test.

* gnu/packages/freedesktop.scm (farstream)
[arguments]: Delete trailing #t.  Rename the disable-timeout-tests phase to
disable-problematic-tests, and disable an extra rtp/recvcodecs test.
Standardize match pattern and update comment.
[native-inputs]: Update the common input.

gnu: gnunet: Update to 0.19.4.

* gnu/packages/gnunet.scm (gnunet): Update to 0.19.4.

gnu: imgui: Update to 1.89.4.

* gnu/packages/toolkits.scm (imgui): Update to 1.89.4.

gnu: openboardview: Use imgui-1.87.

* gnu/packages/electronics.scm (openboardview) [inputs]: Downgrade imgui to
version 1.87.

gnu: Add imgui-1.87.

* gnu/packages/toolkits.scm (imgui-1.87): New variable.

gnu: imgui: Use gexp output variables.

* gnu/packages/toolkits.scm (imgui) [arguments]: Use gexp variables in install
phase.

gnu: utf8-h: Install header under include/utf8 prefix.

This is to standardize with the usage of the library in the package's only
current user, OpenBoardView.  It also matches the installation layout of the
Arch package, which is made by its author.

* gnu/packages/c.scm (utf8-h) [arguments]: Use gexps.  Adjust installation
prefix to 'include/utf8' in install phase.
* gnu/packages/electronics.scm (openboardview)
[arguments]: Delete fix-utf8-include-directive phase.

gnu: gnunet: Update home page.

* gnu/packages/gnunet.scm (gnunet) [home-page]: Update URL.

gnu: openboardview: Update home page.

* gnu/packages/electronics.scm (openboardview) [home-page]: Update URL.

gnu: openboardview: Update to 9.95.0.

* gnu/packages/electronics.scm (openboardview): Update to 9.95.0.
[source]: Apply patch.
[arguments]: Update fix-utf8-include-directive phase.
[inputs]: Add orangeduck-mpc.
* gnu/packages/patches/openboardview-use-system-mpc.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu: Add orangeduck-mpc.

* gnu/packages/c.scm (orangeduck-mpc): New variable.
* gnu/packages/patches/orangeduck-mpc-fix-pkg-config.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu: imgui: Use unsigned int vertex indexes.

* gnu/packages/toolkits.scm (imgui)
[arguments]: Add the "-DImDrawIdx=unsigned int" compiler option to the build
phase.

gnu: blender: Update to 3.3.5.

* gnu/packages/graphics.scm (blender): Update to 3.3.5.

gnu: blender: Use ffmpeg 5.

* gnu/packages/graphics.scm (blender) [inputs]: Replace ffmpeg with ffmpeg-5.

gnu: blender: Use gexps and remove labels.

* gnu/packages/graphics.scm (blender) [arguments]: Use gexps.  Replace the
add-ilmbase-include-path phase by an added -I directive to the CMAKE_CXX_FLAGS
configure flag.
[inputs]: Remove labels.

gnu: gnunet: Disable flaky tests.

* gnu/packages/gnunet.scm (gnunet) [arguments]: Add a
disable-problematic-tests phase.

gnu: gnunet: Fix indentation and use gexps.

* gnu/packages/gnunet.scm (gnunet): Fix indentation.
[arguments]: Use gexps and delete trailing #t.

Merge branch 'master' into staging

gnu: conan: Disable more flaky tests.

* gnu/packages/package-management.scm (conan) [arguments]: Run test suite
verbosely.  Skip the test_toolchain and test_list tests.

gnu: conan: Do not hard-code package versions.

* gnu/packages/package-management.scm (conan) [arguments]: Add #:modules
argument.  Avoid hard-coding package versions in configure-tests phase.