gnu: awesome: Remove obsolete snippet.

* gnu/packages/wm.scm (awesome)[source](snippet): Remove.

gnu/packages/wm.scm

@@ -675,18 +675,6 @@ experience.")
              (sha256
               (base32
                "0kwpbls9h1alxcmvxh5g9qb995fds5b2ngcr44w0ibazkyls2pdc"))
-             (modules '((guix build utils)
-                        (srfi srfi-19)))
-             (snippet
-              ;; Remove non-reproducible timestamp and use the date of the
-              ;; source file instead.
-              '(substitute* "common/version.c"
-                 (("__DATE__ \" \" __TIME__")
-                  (date->string
-                   (time-utc->date
-                    (make-time time-utc 0
-                               (stat:mtime (stat "awesome.c"))))
-                   "\"~c\""))))
              (patches (search-patches "awesome-reproducible-png.patch"))))
     (build-system cmake-build-system)
     (native-inputs `(("asciidoc" ,asciidoc)