Fix the test gh action. Don't download rebar3, but use the one provided by the erlang image

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
     
     strategy:
       matrix:
-        otp_version: [20,22,23]
+        otp_version: [20,21,22,23]
         os: [ubuntu-latest]
       
     container:

Makefile

@@ -8,19 +8,19 @@ REBAR3_URL := https://github.com/erlang/rebar3/releases/download/$(REBAR3_VERSIO
 
 all: compile
 
-./rebar3:
+$(REBAR3):
 	$(ERL) -noshell -s inets -s ssl \
 	 -eval '{ok, saved_to_file} = httpc:request(get, {"$(REBAR3_URL)", []}, [], [{stream, "./rebar3"}])' \
 	 -s init stop
 	chmod +x ./rebar3
 
-compile: rebar3
+compile: $(REBAR3)
 	$(REBAR3) compile
 
 test: compile
 	$(REBAR3) eunit
 
-clean: rebar3
+clean: $(REBAR3)
 	$(REBAR3) clean
 
 distclean: