CI: Remove also gtk-rs-core sys tests

Those tests don't do much interesting, attempting to regen
ffi crates is something already done by cloning the gtk-rs-core repo
and regen/build it

Author: bilelmoussaoui

.github/workflows/main.yaml

@@ -144,8 +144,6 @@ jobs:
         with:
           command: test
           args: --release
-      - name: "Test (tests/sys)"
-        run: tests/sys/test.sh
       - name: "Acquire gtk4-rs"
         uses: actions/checkout@v4
         with:

.gitignore

@@ -1,10 +1,4 @@
 target
-/gio
-/gtk
 /src/gir_version.rs
 /.vscode
-tests/gir-files
-tests/sys/*-sys/**
-tests/sys/sys_build/Cargo.lock
-!tests/sys/*-sys/Cargo.toml
 **.DS_Store