fix: ignore working-tree dirtiness in lsfg-vk-android submodule

Set submodule.app/src/main/cpp/lsfg-vk-android.ignore=dirty in .gitmodules
so git/GitHub Desktop stops flagging the parent repo as having uncommitted
changes whenever the submodule's working tree is dirty.

The dirtiness comes from a chain three levels deep: lsfg-vk-android pulls
in thirdparty/pe-parse, which pulls in tests/assets/corkami-poc-dataset.
The corkami dataset is a collection of intentionally-weird PE files used
to test pe-parse — Windows Defender flags some of them as PUA and
quarantines them, leaving the submodule with deleted files. Those files
aren't consumed by our build (they're pe-parse's own test fixtures), so
hiding the working-tree dirtiness is the right call. The submodule's
commit pin is still tracked normally; only the 'this submodule has
local modifications' notice is suppressed.

Author: TideGear

.gitmodules

@@ -4,3 +4,4 @@
 [submodule "app/src/main/cpp/lsfg-vk-android"]
 	path = app/src/main/cpp/lsfg-vk-android
 	url = https://github.com/GameNative/lsfg-vk-android.git
+	ignore = dirty