docker: makefile was renamed but did not show error util cache was bu…

…sted

Signed-off-by: deadprogram <ron@hybridgroup.com>

Dockerfile

@@ -5,7 +5,7 @@ RUN apt-get update && \
     apt-get install -y apt-utils make cmake clang-15 ninja-build && \
     rm -rf /var/lib/apt/lists/*
 
-COPY ./Makefile /tinygo/Makefile
+COPY ./GNUmakefile /tinygo/GNUmakefile
 
 RUN cd /tinygo/ && \
     make llvm-source