ci: use current LiT itest target

CI failed: https://github.com/lightninglabs/loop/actions/runs/23082982774/job/67447021668?pr=1090

The workflow called `make itest-no-backward-compat`, but
lightning-terminal removed that target in
lightninglabs/lightning-terminal@4cedb44
("itest: remove custom channels tests and backward compat infrastructure").

Author: starius

.github/workflows/main.yml

@@ -177,7 +177,7 @@ jobs:
 
       - name: Run LiT itests
         working-directory: ./lightning-terminal
-        run: make itest-no-backward-compat icase='terminal .*'
+        run: make itest icase='terminal .*'
 
   ########################
   # Run LiTd unit tests