gnu: Remove BUILD_TESTING configuration flag.

* gnu/packages/assembly.scm (cpu-features),
* gnu/packages/astronomy.scm (casacore),
* gnu/packages/bioinformatics.scm (morpheus),
* gnu/packages/code.scm (rtags),
* gnu/packages/education.scm (gcompris-qt),
* gnu/packages/game-development.scm (libccd),
* gnu/packages/geo.scm (cloudcompare),
* gnu/packages/glib.scm (dbus-cxx),
* gnu/packages/graph.scm (faiss),
* gnu/packages/graphics.scm (f3d, mmg),
* gnu/packages/i2p.scm (i2pd),
* gnu/packages/image-processing.scm (vtk),
* gnu/packages/image.scm (openjpeg),
* gnu/packages/irc.scm (quassel),
* gnu/packages/jami.scm (jami),
* gnu/packages/kde.scm (kapptemplate, kdeconnect, kdenlive, krita),
* gnu/packages/kde-frameworks.scm (purpose, purpose-5),
* gnu/packages/kde-office.scm (calligra, ghostwriter),
* gnu/packages/linux.scm (bpftrace),
* gnu/packages/maths.scm (blitz, double-conversion, hpcombi, lapack,
vc),
* gnu/packages/messaging.scm (libsignal-protocol-c),
* gnu/packages/mold.scm (mold),
* gnu/packages/music.scm (sonivox),
* gnu/packages/networking.scm (dhtnet),
* gnu/packages/opencl.scm (opencl-clhpp),
* gnu/packages/openpgp.scm (rnp),
* gnu/packages/photo.scm (darktable),
* gnu/packages/popt.scm (gflags),
* gnu/packages/rdesktop.scm (freerdp),
* gnu/packages/security-token.scm (cppcodec),
* gnu/packages/terminals.scm (libtsm),
* gnu/packages/text-editors.scm (jucipp),
* gnu/packages/xdisorg.scm (xsettingsd)
[arguments]<#:configure-flags>: Remove BUILD_TESTING.

* gnu/packages/jupyter.scm (xeus)
[arguments]: Disable tests.
<#:configure-flags>: Remove BUILD_TESTING.

Change-Id: I6870720cdd2b10c7afacf0c6e7400cd1d73a1209

gnu/packages/code.scm

@@ -711,8 +711,7 @@ possible to collect coverage information without special compiler switches.")
     (arguments
      '(#:build-type "RelWithDebInfo"
        #:configure-flags
-       '("-DRTAGS_NO_ELISP_FILES=1"
-         "-DBUILD_TESTING=FALSE")
+       '("-DRTAGS_NO_ELISP_FILES=1")
        #:tests? #f))
     (native-inputs
      (list pkg-config))