CI runners: update macOS 12 -> 13 (still x86)

Author: Bromeon

.github/workflows/full-ci.yml

@@ -237,19 +237,19 @@ jobs:
           # macOS -- for the unintuitive naming, see https://github.com/actions/runner-images?tab=readme-ov-file#available-images
 
           - name: macos-x86
-            os: macos-12
+            os: macos-13
             artifact-name: macos-x86-nightly
             godot-binary: godot.macos.editor.dev.x86_64
             with-hot-reload: true
 
           - name: macos-double-x86
-            os: macos-12
+            os: macos-13
             artifact-name: macos-double-x86-nightly
             godot-binary: godot.macos.editor.dev.double.x86_64
             rust-extra-args: --features godot/api-custom,godot/double-precision
 
           - name: macos-x86-4.2
-            os: macos-12
+            os: macos-13
             artifact-name: macos-x86-4.2
             godot-binary: godot.macos.editor.dev.x86_64
             godot-prebuilt-patch: '4.2.2'