Fix CI for GHC 9.6: stack --silent supresses warning about too new GHC

Author: andreasabel

.github/workflows/ci.yml

@@ -104,4 +104,4 @@ jobs:
         stackyaml: ${{ matrix.plan.stackyaml }}
       run: |
         export PATH=~/.local/bin:$PATH
-        STACKYAML=$stackyaml make test
+        make STACKYAMLOPT="--silent --stack-yaml=$stackyaml" test

Makefile

@@ -18,7 +18,7 @@ SHELLTESTEXE = $(shell $(STACK) path --local-install-root)/bin/shelltest
 # the base shelltest command with common options,
 # and the STACKYAMLOPT env var which helps any tests
 # which run stack themselves (eg large-output.test)
-SHELLTEST = STACKYAMLOPT=$(STACKYAMLOPT) $(SHELLTESTEXE) --exclude /_ -j16 --hide-successes
+SHELLTEST = STACKYAMLOPT="$(STACKYAMLOPT)" $(SHELLTESTEXE) --exclude /_ -j16 --hide-successes
 
 # standard targets