Add ci flag to CI

- set -Werror in CI
- fix GHC 9.2 warning about TH looking syntax ($e)

.github/workflows/haskell-ci.yml

@@ -198,6 +198,7 @@ jobs:
           echo "package swarm" >> cabal.project
           echo "    ghc-options: -Werror=missing-methods" >> cabal.project
           cat >> cabal.project <<EOF
+          flags: +ci
           EOF
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: $_ installed\n" unless /^(swarm)$/; }' >> cabal.project.local
           cat cabal.project

cabal.haskell-ci

@@ -21,4 +21,7 @@ benchmarks: True
 hlint: True
 hlint-job: 9.0.2
 hlint-yaml: .hlint.yaml
-hlint-download-binary: True
+hlint-download-binary: True
+
+raw-project
+  flags: +ci