fix(android): enable ETC2/ASTC import + use versioned editor settings

Two fixes that finally land the Android export. Verified locally
with godot 4.6.2-arch + downloaded 4.6 templates + Android SDK.

- project.godot: add
  rendering/textures/vram_compression/import_etc2_astc=true.
  Without it Godot refuses the Android export with "La plateforme
  cible nécessite une compression de texture « ETC2/ASTC »". In
  headless mode this surfaces as an *empty* configuration-errors
  block, which is what kept us stuck in CI.

- workflow: write Godot editor settings to
  editor_settings-${GODOT_VERSION}.tres (i.e. -4.6.tres on 4.6),
  not -4.tres. Godot 4.5+ uses a minor-version-suffixed settings
  file; the major-only name is ignored by 4.6, so our injected
  android_sdk_path / java_sdk_path / debug_keystore never reached
  the export plugin.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -167,7 +167,9 @@ jobs:
       - name: Write Godot editor settings (Android SDK / JDK paths)
         run: |
           mkdir -p ~/.config/godot
-          cat > ~/.config/godot/editor_settings-4.tres <<EOF
+          # Godot 4.5+ uses a minor-version-suffixed settings file
+          # (editor_settings-4.6.tres for 4.6), not the major-only -4.tres.
+          cat > ~/.config/godot/editor_settings-${GODOT_VERSION}.tres <<EOF
           [gd_resource type="EditorSettings" format=3]
           [resource]
           export/android/android_sdk_path = "${ANDROID_HOME}"

project.godot

@@ -67,4 +67,5 @@ locale/translations=PackedStringArray("res://locales/fr.po", "res://locales/en.p
 
 [rendering]
 
+textures/vram_compression/import_etc2_astc=true
 environment/defaults/default_environment="res://default_env.tres"