ci: Run GUI unit tests in cross-Windows task

.github/workflows/ci.yml

@@ -433,6 +433,7 @@ jobs:
       - name: Run unit tests
         # Can't use ctest here like other jobs as we don't have a CMake build tree.
         run: |
+          ./bin/test_bitcoin-qt.exe
           ./bin/test_bitcoin.exe -l test_suite  # Intentionally run sequentially here, to catch test case failures caused by dirty global state from prior test cases.
           ./src/secp256k1/bin/exhaustive_tests.exe
           ./src/secp256k1/bin/noverify_tests.exe