SCons: Format buildsystem files with psf/black

Configured for a max line length of 120 characters.

psf/black is very opinionated and purposely doesn't leave much room for
configuration. The output is mostly OK so that should be fine for us,
but some things worth noting:

- Manually wrapped strings will be reflowed, so by using a line length
  of 120 for the sake of preserving readability for our long command
  calls, it also means that some manually wrapped strings are back on
  the same line and should be manually merged again.

- Code generators using string concatenation extensively look awful,
  since black puts each operand on a single line. We need to refactor
  these generators to use more pythonic string formatting, for which
  many options are available (`%`, `format` or f-strings).

- CI checks and a pre-commit hook will be added to ensure that future
  buildsystem changes are well-formatted.

modules/freetype/SCsub

@@ -1,12 +1,12 @@
 #!/usr/bin/env python
 
-Import('env')
-Import('env_modules')
+Import("env")
+Import("env_modules")
 
 env_freetype = env_modules.Clone()
 
 # Thirdparty source files
-if env['builtin_freetype']:
+if env["builtin_freetype"]:
     thirdparty_dir = "#thirdparty/freetype/"
     thirdparty_sources = [
         "src/autofit/autofit.c",
@@ -53,31 +53,31 @@ if env['builtin_freetype']:
     ]
     thirdparty_sources = [thirdparty_dir + file for file in thirdparty_sources]
 
-    if env['platform'] == 'uwp':
+    if env["platform"] == "uwp":
         # Include header for UWP to fix build issues
-        env_freetype.Append(CCFLAGS=['/FI', '"modules/freetype/uwpdef.h"'])
+        env_freetype.Append(CCFLAGS=["/FI", '"modules/freetype/uwpdef.h"'])
         # Globally too, as freetype is used in scene (see bottom)
-        env.Append(CCFLAGS=['/FI', '"modules/freetype/uwpdef.h"'])
+        env.Append(CCFLAGS=["/FI", '"modules/freetype/uwpdef.h"'])
 
     env_freetype.Prepend(CPPPATH=[thirdparty_dir + "/include"])
     # Also needed in main env for scene/
     env.Prepend(CPPPATH=[thirdparty_dir + "/include"])
 
-    env_freetype.Append(CPPDEFINES=['FT2_BUILD_LIBRARY', 'FT_CONFIG_OPTION_USE_PNG'])
-    if (env['target'] == 'debug'):
-        env_freetype.Append(CPPDEFINES=['ZLIB_DEBUG'])
+    env_freetype.Append(CPPDEFINES=["FT2_BUILD_LIBRARY", "FT_CONFIG_OPTION_USE_PNG"])
+    if env["target"] == "debug":
+        env_freetype.Append(CPPDEFINES=["ZLIB_DEBUG"])
 
     # Also requires libpng headers
-    if env['builtin_libpng']:
+    if env["builtin_libpng"]:
         env_freetype.Prepend(CPPPATH=["#thirdparty/libpng"])
 
-    sfnt = thirdparty_dir + 'src/sfnt/sfnt.c'
+    sfnt = thirdparty_dir + "src/sfnt/sfnt.c"
     # Must be done after all CPPDEFINES are being set so we can copy them.
-    if env['platform'] == 'javascript':
+    if env["platform"] == "javascript":
         # Forcibly undefine this macro so SIMD is not used in this file,
         # since currently unsupported in WASM
         tmp_env = env_freetype.Clone()
-        tmp_env.Append(CPPFLAGS=['-U__OPTIMIZE__'])
+        tmp_env.Append(CPPFLAGS=["-U__OPTIMIZE__"])
         sfnt = tmp_env.Object(sfnt)
     thirdparty_sources += [sfnt]
 
@@ -91,7 +91,7 @@ if env['builtin_freetype']:
     # and then plain strings for system library. We insert between the two.
     inserted = False
     for idx, linklib in enumerate(env["LIBS"]):
-        if isinstance(linklib, (str, bytes)): # first system lib such as "X11", otherwise SCons lib object
+        if isinstance(linklib, (str, bytes)):  # first system lib such as "X11", otherwise SCons lib object
             env["LIBS"].insert(idx, lib)
             inserted = True
             break

modules/freetype/config.py

@@ -1,5 +1,6 @@
 def can_build(env, platform):
     return True
 
+
 def configure(env):
     pass