Update project for Godot version 4.2 (#64)

* Update project for Godot version 4.2

* CI: Fix MinGW install error by pinning to earlier version

Same as for godot-cpp MinGW doesn't work with the newest version so the version is pinned to an earlier version: godotengine/godot-cpp#1259

.github/workflows/builds.yml

@@ -84,6 +84,8 @@ jobs:
       - name: Setup MinGW for Windows/MinGW build
         if: ${{ matrix.platform == 'windows' }}
         uses: egor-tensin/setup-mingw@v2
+        with:
+          version: 12.2.0
 
       - name: Compile godot-cpp
         shell: sh

game/project.godot

@@ -1,9 +1,17 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
 config_version=5
 
 [application]
 
 config/name="GDExtensionSummator"
 config/tags=PackedStringArray("gdextension", "template")
 run/main_scene="res://main.tscn"
-config/features=PackedStringArray("4.1")
+config/features=PackedStringArray("4.2")
 config/icon="res://icon.png"