meson: use builtin support for reading version from a file

In meson 0.57 support was added for reading a version from a file to
meson natively, so we don't need this workaround anymore.

Reviewed-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20752>

bin/meson_get_version.py

@@ -1,39 +0,0 @@
-#!/usr/bin/env python3
-# encoding=utf-8
-# Copyright © 2017 Intel Corporation
-
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-# SOFTWARE.
-
-import argparse
-import os
-
-
-def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument('version_dir', help="Directory with VERSION file")
-    args = parser.parse_args()
-
-    filename = os.path.join(args.version_dir, 'VERSION')
-    with open(filename) as f:
-        version = f.read().strip()
-    print(version, end='')
-
-
-if __name__ == '__main__':
-    main()