Clean up "GDScript" extension use from conf.py.

_extensions/gdscript.py

@@ -1578,7 +1578,10 @@ class GDScriptLexer(RegexLexer):
 
 
 def setup(sphinx):
+    from sphinx.highlighting import lexers
+
     sphinx.add_lexer("gdscript", GDScriptLexer)
+    lexers["gdscript"] = GDScriptLexer()
 
     return {
         "parallel_read_safe": True,

conf.py

@@ -19,6 +19,7 @@ extensions = [
     "sphinxext.opengraph",
     "sphinx_copybutton",
     "sphinxcontrib.video",
+    "gdscript",
 ]
 
 # Warning when the Sphinx Tabs extension is used with unknown
@@ -44,9 +45,6 @@ ogp_social_cards = {
     "enable": False
 }
 
-if not os.getenv("SPHINX_NO_GDSCRIPT"):
-    extensions.append("gdscript")
-
 if not os.getenv("SPHINX_NO_DESCRIPTIONS"):
     extensions.append("godot_descriptions")
 
@@ -119,16 +117,6 @@ print("Build language: {}, i18n tag: {}".format(language, is_i18n))
 
 exclude_patterns = [".*", "**/.*", "_build", "_tools"]
 
-# fmt: off
-# These imports should *not* be moved to the start of the file,
-# they depend on the sys.path.append call registering "_extensions".
-# GDScript syntax highlighting
-from gdscript import GDScriptLexer
-from sphinx.highlighting import lexers
-
-lexers["gdscript"] = GDScriptLexer()
-# fmt: on
-
 smartquotes = False
 
 # Pygments (syntax highlighting) style to use