refine meson git version

misc/meson-vcs-tag.sh

@@ -1,22 +0,0 @@
-#!/bin/bash
-
-set -eu
-set -o pipefail
-
-dir="$1"
-tag="$2"
-fallback="$3"
-
-if [ -n "$tag" ]; then
-    echo "$tag"
-    exit 0
-fi
-
-# Apparently git describe has a bug where it always considers the work-tree
-# dirty when invoked with --git-dir (even though 'git status' is happy). Work
-# around this issue by cd-ing to the source directory.
-cd "$dir"
-# Check that we have either .git/ (a normal clone) or a .git file (a work-tree)
-# and that we don't get confused if a tarball is extracted in a higher-level
-# git repository.
-[ -e .git ] && git describe --abbrev=7 --dirty=+ 2>/dev/null | sed 's/^v//' || echo "$fallback"