fix: GitHub License Detection (#1657)

GitHub fails to detect the license of GT4Py correctly (thus we get the
ugly banner
![license](https://img.shields.io/github/license/GridTools/gt4py)).
GitHub uses [licensee](https://github.com/licensee/licensee/) to detect
the license as documented
[here](https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/licensing-a-repository#detecting-a-license).
This PR fixes license detection using licensee, which previously was
broken due to an additional line above the typical BSD-3 copyright
notice and the file `LICENSE_HEADER.txt` which confused licensee, too.

.pre-commit-config.yaml

@@ -34,7 +34,7 @@ repos:
   - id: insert-license
     exclude: ^\..*$
     types: [python]
-    args: [--comment-style, "|#|", --license-filepath, ./LICENSE_HEADER.txt, --fuzzy-match-generates-todo]
+    args: [--comment-style, "|#|", --license-filepath, ./HEADER.txt, --fuzzy-match-generates-todo]
 
 - repo: https://github.com/pre-commit/pre-commit-hooks
   rev: v4.4.0

CODING_GUIDELINES.md

@@ -105,7 +105,7 @@ We highly encourage the [doctest][doctest] format for code examples in docstring
 In general, you should structure new Python modules in the following way:
 
 1. _shebang_ line: `#! /usr/bin/env python3` (only for **executable scripts**!).
-2. License header (see `LICENSE_HEADER.txt`).
+2. License header (see `HEADER.txt`).
 3. Module docstring.
 4. Imports, alphabetically ordered within each block (fixed automatically by `ruff-formatter`):
    1. Block of imports from the standard library.

LICENSE.txt

@@ -1,5 +1,3 @@
-  GT4Py - GridTools Framework
-
   Copyright (c) 2014-2024, ETH Zurich
   All rights reserved.