Stop passing YACC arg for make

After ruby/ruby#7798, ruby uses lrama
as default then no need to pass YACC anymore.

Author: yui-knk

.github/workflows/test.yaml

@@ -84,5 +84,5 @@ jobs:
       - run: sudo apt-get --purge remove bison
       - run: ../autogen.sh
       - run: ../configure -C --disable-install-doc
-      - run: make YACC=$(readlink -f $(pwd)/../tool/lrama/exe/lrama)
+      - run: make
       - run: make test-all