gnu: Remove unneeded module imports.

* gnu/packages/abiword.scm,
* gnu/packages/ada.scm,
* gnu/packages/agda.scm,
* gnu/packages/backup.scm,
* gnu/packages/barrier.scm,
* gnu/packages/bioinformatics.scm,
* gnu/packages/bootstrap.scm,
* gnu/packages/bqn.scm,
* gnu/packages/c.scm,
* gnu/packages/chemistry.scm,
* gnu/packages/coq.scm,
* gnu/packages/cross-base.scm,
* gnu/packages/databases.scm,
* gnu/packages/emacs-xyz.scm,
* gnu/packages/enlightenment.scm,
* gnu/packages/games.scm,
* gnu/packages/geo.scm,
* gnu/packages/ghostscript.scm,
* gnu/packages/gl.scm,
* gnu/packages/golang.scm,
* gnu/packages/jami.scm,
* gnu/packages/java-maths.scm,
* gnu/packages/kde-frameworks.scm,
* gnu/packages/kde-plasma.scm,
* gnu/packages/language.scm,
* gnu/packages/libreoffice.scm,
* gnu/packages/linphone.scm,
* gnu/packages/lisp.scm,
* gnu/packages/llvm.scm,
* gnu/packages/machine-learning.scm,
* gnu/packages/minetest.scm,
* gnu/packages/monitoring.scm,
* gnu/packages/nfs.scm,
* gnu/packages/ocr.scm,
* gnu/packages/opencl.scm,
* gnu/packages/pdf.scm,
* gnu/packages/python-xyz.scm,
* gnu/packages/racket.scm,
* gnu/packages/rust.scm,
* gnu/packages/syncthing.scm,
* gnu/packages/syndication.scm,
* gnu/packages/telegram.scm,
* gnu/packages/vulkan.scm,
* gnu/packages/web-browsers.scm,
* gnu/packages/web.scm,
* gnu/packages/webkit.scm: Remove some unecessary module imports.

gnu/packages/cross-base.scm

@@ -38,7 +38,6 @@
   #:use-module (guix i18n)
   #:use-module (guix utils)
   #:use-module (guix build-system gnu)
-  #:use-module (guix build-system trivial)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:use-module (ice-9 match)