Fix missing GDExtension in-editor API reference

[akien-mga]

This commit partially reverts e1ce034 (#76431), keeping the core changes which should still be safe.
It also reverts 67e8c57 (#77578) which depends on e1ce034.

This commit partially reverts a change in e1ce034 (#76431) which would prevent from generating API reference for GDExtension APIs.

Fixes #78829.

Another option could be to revert all changes related to the docs cache and revisit it for 4.2, as it's current disabled anyway, and those changes had bigger implications as seen here. But this surgical revert might be enough.

[akien-mga]

Just tested that reverting only this part is enough to fix the regression:

diff --git a/editor/doc_tools.cpp b/editor/doc_tools.cpp
index 91358c3475..780b3169b4 100644
--- a/editor/doc_tools.cpp
+++ b/editor/doc_tools.cpp
@@ -374,11 +374,6 @@ void DocTools::generate(bool p_basic_types) {
 				classes.pop_front();
 				continue;
 			}
-			if (ClassDB::get_api_type(name) != ClassDB::API_CORE && ClassDB::get_api_type(name) != ClassDB::API_EDITOR) {
-				print_verbose(vformat("Class '%s' belongs neither to core nor editor, skipping.", name));
-				classes.pop_front();
-				continue;
-			}
 
 			String cname = name;
 			// Property setters and getters do not get exposed as individual methods.

Another option would be to add API_EXTENSION to the list of allowed APIs, but then I'm not sure what we're excluding anymore.

[akien-mga]

Just tested that reverting only this part is enough to fix the regression:

Pushed that, so it's more minimal.

[RandomShaper]

Just tested that reverting only this part is enough to fix the regression:

diff --git a/editor/doc_tools.cpp b/editor/doc_tools.cpp
index 91358c3475..780b3169b4 100644
--- a/editor/doc_tools.cpp
+++ b/editor/doc_tools.cpp
@@ -374,11 +374,6 @@ void DocTools::generate(bool p_basic_types) {
 				classes.pop_front();
 				continue;
 			}
-			if (ClassDB::get_api_type(name) != ClassDB::API_CORE && ClassDB::get_api_type(name) != ClassDB::API_EDITOR) {
-				print_verbose(vformat("Class '%s' belongs neither to core nor editor, skipping.", name));
-				classes.pop_front();
-				continue;
-			}
 
 			String cname = name;
 			// Property setters and getters do not get exposed as individual methods.

Another option would be to add API_EXTENSION to the list of allowed APIs, but then I'm not sure what we're excluding anymore.

Only API_NONE would remain. So the if could be changed so those are discarded. That said, I think we have some overlap between API_NONE and not exposed classes, but that's another topic.