Cleanup: declare __all__ for Python scripts

Declare all to make public public API's explicit and
help detect unused code.

tests/python/bl_animation_drivers.py

@@ -2,16 +2,19 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+"""
+blender -b --factory-startup --python tests/python/bl_animation_drivers.py -- --testdir /path/to/tests/data/animation
+"""
+__all__ = (
+    "main",
+)
+
 import unittest
 import bpy
 import pathlib
 import sys
 from rna_prop_ui import rna_idprop_quote_path
 
-"""
-blender -b --factory-startup --python tests/python/bl_animation_drivers.py -- --testdir /path/to/tests/data/animation
-"""
-
 
 class AbstractEmptyDriverTest:
     def setUp(self):

tests/python/bl_blendfile_liblink.py

@@ -2,7 +2,13 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-# ./blender.bin --background --python tests/python/bl_blendfile_liblink.py
+"""
+./blender.bin --background --python tests/python/bl_blendfile_liblink.py
+"""
+__all__ = (
+    "main",
+)
+
 import bpy
 import os
 import sys

tests/python/bl_blendfile_versioning.py

@@ -9,6 +9,10 @@
 #
 # This needs to be investigated!
 
+__all__ = (
+    "main",
+)
+
 import os
 import platform
 import sys

tests/python/bl_imbuf_load.py

@@ -2,6 +2,10 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+__all__ = (
+    "main",
+)
+
 import os
 import pathlib
 import sys

tests/python/bl_io_curve_svg_test.py

@@ -3,6 +3,10 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+__all__ = (
+    "main",
+)
+
 import argparse
 import os
 import sys

tests/python/bl_load_addons.py

@@ -7,6 +7,9 @@
 """
 ./blender.bin --background --factory-startup --python tests/python/bl_load_addons.py
 """
+__all__ = (
+    "main",
+)
 
 import bpy
 import addon_utils

tests/python/bl_mesh_validate.py

@@ -5,6 +5,10 @@
 # Simple script to check mash validate code.
 # XXX Should be extended with many more "wrong cases"!
 
+__all__ = (
+    "main",
+)
+
 import bpy
 
 import random

tests/python/bl_pyapi_bpy_utils_units.py

@@ -3,6 +3,11 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # ./blender.bin --background --python tests/python/bl_pyapi_bpy_utils_units.py -- --verbose
+
+__all__ = (
+    "main",
+)
+
 import unittest
 
 from bpy.utils import units
@@ -93,7 +98,11 @@ class UnitsTesting(unittest.TestCase):
             )
 
 
-if __name__ == '__main__':
+def main():
     import sys
     sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [])
     unittest.main()
+
+
+if __name__ == '__main__':
+    main()

tests/python/modules/imbuf_test.py

@@ -2,6 +2,10 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+__all__ = (
+    "AbstractImBufTest",
+)
+
 import os
 import pathlib
 import shutil