gnu: Use xxd instead of vim.

* gnu/packages/audio.scm (faust-2)[native-inputs]: Replace vim with xxd.
* gnu/packages/avr.scm (microscheme)[native-inputs]: Likewise.
* gnu/packages/bioinformatics.scm (star)[native-inputs]: Likewise.
* gnu/packages/disk.scm (dosfstools)[native-inputs]: Likewise.
* gnu/packages/package-management.scm (diffoscope)[inputs]: Likewise.

gnu/packages/audio.scm

@@ -1078,7 +1078,7 @@ PS, and DAB+.")
     (native-inputs
      `(("llvm" ,llvm-with-rtti)
        ("which" ,which)
-       ("xxd" ,vim)
+       ("xxd" ,xxd)
        ("ctags" ,emacs-minimal)  ; for ctags
        ("pkg-config" ,pkg-config)))
     (inputs

gnu/packages/avr.scm

@@ -157,7 +157,7 @@ C++.")
        (list (string-append "PREFIX=" (assoc-ref %outputs "out")))))
     (native-inputs
      `(("unzip" ,unzip)
-       ("vim" ,vim))) ; for xxd
+       ("xxd" ,xxd)))
     (home-page "http://microscheme.org/")
     (synopsis "Scheme subset for Atmel microcontrollers")
     (description

gnu/packages/bioinformatics.scm

@@ -5408,7 +5408,7 @@ application of SortMeRNA is filtering rRNA from metatranscriptomic data.")
              #t))
          (delete 'configure))))
     (native-inputs
-     `(("vim" ,vim))) ; for xxd
+     `(("xxd" ,xxd)))
     (inputs
      `(("htslib" ,htslib)
        ("zlib" ,zlib)))

gnu/packages/disk.scm

@@ -216,7 +216,7 @@ to recover data more efficiently by only reading the necessary blocks.")
      `(#:make-flags (list (string-append "PREFIX=" %output)
                           "CC=gcc")))
     (native-inputs
-     `(("xxd" ,vim))) ; for tests
+     `(("xxd" ,xxd))) ; for tests
     (home-page "https://github.com/dosfstools/dosfstools")
     (synopsis "Utilities for making and checking MS-DOS FAT file systems")
     (description

gnu/packages/package-management.scm

@@ -538,7 +538,7 @@ transactions from C or Python.")
               ("python-libarchive-c" ,python-libarchive-c)
               ("python-tlsh" ,python-tlsh)
               ("colordiff" ,colordiff)
-              ("xxd" ,vim)
+              ("xxd" ,xxd)
 
               ;; Below are modules used for tests.
               ("python-pytest" ,python-pytest)