Fix broken build due to happy-1.21.0

haskell/happy#211

[changelog skip]

.github/workflows/build.yaml

@@ -16,7 +16,7 @@ jobs:
         resolver:
         - lts-16.31
         - lts-18.16
-        - nightly-2021-11-06
+        - nightly-2021-11-15
     steps:
     - uses: actions/checkout@v2
     - uses: dahlia/actions/setup-yq@main
@@ -48,6 +48,8 @@ jobs:
             .resolver | test("^nightly-")
            )
         | .flags.seonbi.iconv = (strenv(OS) | test("^windows-") | not)
+        | .flags.happy.bootstrap = (.resolver | test("^nightly-"))
+        | del(.flags.happy | select(.bootstrap | not))
         ' stack.yaml
       env:
         RESOLVER: ${{ matrix.resolver }}
@@ -72,9 +74,9 @@ jobs:
         [[ "$tag_ver" = "$pkg_ver" ]]
         ! grep -i "to be released" CHANGES.md
     - name: Resolve dependencies
-      run: stack install --only-dependencies
+      run: stack install --test --only-dependencies
     - name: Build
-      run: stack build
+      run: stack build --test
     - name: Test
       run: stack test
     - name: Package source distribution