cmake: Use full signature of add_test() command

An executable target in the `COMMAND` option will automatically be
replaced by the location of the executable created at build time.

This change fixes tests for Windows binaries using Wine.

.cirrus.yml

@@ -403,7 +403,7 @@ task:
     - cmake --build build --config RelWithDebInfo -- -property:UseMultiToolTask=true;CL_MPcount=5
   check_script:
     - '%x64_NATIVE_TOOLS%'
-    - ctest --test-dir build -j 5
+    - ctest -C RelWithDebInfo --test-dir build -j 5
     - build\src\RelWithDebInfo\bench_ecmult.exe
     - build\src\RelWithDebInfo\bench_internal.exe
     - build\src\RelWithDebInfo\bench.exe