pre-commit: Workaround broken shebang on Windows

Using "python" in the shebang breaks those scripts when ran outside of
pre-commit venv.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9080>

.pre-commit-config.yaml

@@ -1,3 +1,10 @@
+# Notes:
+# - Python commands must be prefixed with `python` because pre-commit refuses to
+#   special-case shebangs on Windows where `python3` does not commonly exists.
+#   Luckily, the `python` command exists in the virtualenv created by pre-commit
+#   on all platforms. https://github.com/pre-commit/pre-commit/issues/3415,
+#   https://github.com/pre-commit/pre-commit/issues/3468
+
 fail_fast: false
 repos:
 -   repo: https://github.com/jorisroovers/gitlint
@@ -16,7 +23,7 @@ repos:
     -   id: gst-indent
         name: gst-indent
         language: python
-        entry: ./scripts/gst-indent-all.py
+        entry: python ./scripts/gst-indent-all.py
         pass_filenames: false
         types_or: ["c", "c++"]
         additional_dependencies: ["gst-indent==1.0.0"]
@@ -30,6 +37,6 @@ repos:
     -   id: doc-checks
         name: doc-checks
         language: python
-        entry: ./scripts/git-hooks/pre-commit-python.hook
+        entry: python ./scripts/git-hooks/pre-commit-python.hook
         pass_filenames: false
         additional_dependencies: ["autopep8==2.3.2", "pycodestyle==2.12.1"]

scripts/gst-indent-all.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from itertools import filterfalse
 import os
@@ -6,6 +6,7 @@ import re
 import subprocess
 from gst_indent_common import indent
 
+
 def readfile(f):
     if os.path.exists(f):
         expressions = open(f, 'r', encoding='utf-8').read().splitlines()

scripts/gst-indent.py

@@ -1,8 +1,8 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from sys import argv
 from gst_indent_common import indent
 
 
 if __name__ == '__main__':
-    indent(argv[1:])
+    indent(*argv[1:])