Remove contrib/_incr_version

Not used anymore.

contrib/_incr_version

@@ -1,28 +0,0 @@
-#!/bin/sh -eu
-old_version="$1"
-new_version="$2"
-sed -i meson.build -e "s/version: '$old_version'/version: '$new_version'/g"
-
-bugfix='n'
-printf "Breaking API changes? (y/n) "
-read breaking
-if [ "$breaking" = 'n' ]
-then
-	printf "Bugfix release (no backwards-incompatible ABI changes)? (y/n) "
-	read bugfix
-fi
-
-soversion=$(egrep '^soversion =' meson.build | cut -d'=' -f2-)
-soversion=$((soversion))
-
-if [ "$bugfix" != 'y' ]
-then
-	soversion=$((soversion+1))
-fi
-
-sed -i meson.build \
-	-e "s/soversion = .*/soversion = $soversion/g"
-
-exit 1
-git add meson.build
-git commit -m "Update version to $new_version"