Add tool to run black on the whole project

.github/tools/run_black.sh

@@ -0,0 +1,68 @@
+#!/bin/bash
+# Exit on error, print commands
+set -ex
+#
+# Copyright (c) Odd Stråbø, 2024
+# File-License: the Unlicense
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# 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 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.
+#
+# For more information, please refer to <http://unlicense.org/>
+#
+
+# Ensure we are in the repository root
+pushd "$(realpath $(dirname $0)/../..)"
+
+# Make sure black is installed and up to date
+pipx upgrade black
+
+# Make sure we are on latest master
+git checkout master
+git fetch upstream master
+git pull upstream master --ff-only
+
+# Create new branch, deleting if existing
+git checkout -B black
+
+# Ensure workdir is clean
+git stash --include-untracked
+git reset --hard
+
+# Run black and git add changed files
+black . -t py38 -t py39 -t py310 -t py311 -t py312 -t py313 2>&1 | sed -nr 's/^reformatted\s(.*)$/\1/p' | tr '\n' '\0' | xargs -0 git add
+
+# Commit changes
+git commit -m 'Tool black: auto-format Python code'
+
+# Hide previous commit from blame to avoid clutter
+echo "# Tool: black" >>.git-blame-ignore-revs
+git rev-parse HEAD >>.git-blame-ignore-revs
+git add .git-blame-ignore-revs
+git commit -m 'Tool black: ignore blame'
+
+# Push branch to fork
+git push --set-upstream origin black --force
+
+# Go back to previous directory
+popd