CI: Fix dumping GDExtension interface and API for godot-cpp

Follow-up to https://github.com/godotengine/godot-cpp/pull/960.

Fix exit code for --dump-extension-api and --dump-gdextension-interface.

Removed the planned API validation step as we still didn't implement
anything, and maintaining a stub isn't useful.

.github/workflows/linux_builds.yml

@@ -198,20 +198,13 @@ jobs:
           submodules: 'recursive'
           path: 'godot-cpp'
 
-      # Check extension API
-      - name: Check for extension api updates
+      # Dump GDExtension interface and API
+      - name: Dump GDExtension interface and API for godot-cpp build
         if: ${{ matrix.godot-cpp-test }}
         run: |
-          echo "Running --dump-extension-api to create extensions api."
-          VK_ICD_FILENAMES=$(pwd)/vk_swiftshader_icd.json DRI_PRIME=0 xvfb-run ${{ matrix.bin }} --audio-driver Dummy --dump-extension-api 2>&1 > /dev/null || true
-          misc/scripts/compare_extension_api.py godot-cpp/godot-headers/extension_api.json extension_api.json
-
-      # Copy new extension API files into place
-      - name: Copy new extension API files into place
-        if: ${{ matrix.godot-cpp-test }}
-        run: |
-          cp -f extension_api.json godot-cpp/godot-headers/
-          cp -f core/extension/gdextension_interface.h godot-cpp/godot-headers/godot/
+          ${{ matrix.bin }} --headless --dump-gdextension-interface --dump-extension-api
+          cp -f gdextension_interface.h godot-cpp/gdextension/
+          cp -f extension_api.json godot-cpp/gdextension/
 
       # Build godot-cpp test extension
       - name: Build godot-cpp test extension

main/main.cpp

@@ -2594,6 +2594,7 @@ bool Main::start() {
 	}
 
 	if (dump_gdextension_interface || dump_extension_api) {
+		OS::get_singleton()->set_exit_code(EXIT_SUCCESS);
 		return false;
 	}
 

misc/scripts/compare_extension_api.py

@@ -1,11 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-import sys
-
-# TODO:
-# Add a process that compares the original godot-cpp/godot-headers/extension_api.json with the new extension_api.json (both passed as arguments) and reports any API calls that have been removed.
-# If we only have additions or no changes to the file, we pass
-# For now we deem this too early because the API isn't stable enough yet.
-
-sys.exit(0)