only keep nix-build for CI

.github/workflows/CI.yaml

@@ -17,47 +17,4 @@ jobs:
       - name: Build weiss-xmonad
         run: nix build -L
       - name: Build weiss-xmonad shell
-        run: nix build -L '.#devShells.x86_64-linux.default'
-
-  stack-build:
-    name: Stack ${{ matrix.resolver }} on ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        resolver: [ nightly, lts-19, lts-18, lts-17, lts-16, lts-15, lts-14 ]
-        os: [ macos-latest, ubuntu-latest ]
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v2
-      - uses: haskell/actions/setup@v1
-        with:
-          enable-stack: true
-      ## For some reason, stack caching seems to be very brittle, and cause a lot of build failures.
-      ## I haven't investigated very thoroughly what to best do about this, but for now, I'm just not caching stack builds.
-      - run: stack init --resolver ${{ matrix.resolver }}
-      - run: stack build --resolver ${{ matrix.resolver }} --only-dependencies
-      - run: stack build --resolver ${{ matrix.resolver }}
-      - run: stack build --resolver ${{ matrix.resolver }} --haddock --test --bench --no-run-benchmarks
-
-  cabal-build:
-    name: Cabal with GHC ${{ matrix.ghc }} on ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        ghc: [ '8.6.5', '8.8.3', '8.10.7', '9.0.2', '9.2.2' ]
-        os: [ ubuntu-latest, macos-latest ]
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v2
-      - uses: haskell/actions/setup@v1
-        with:
-          ghc-version: ${{ matrix.ghc }}
-      - uses: actions/cache@v2
-        with:
-          path: |
-            ~/.cabal
-            dist-newstyle
-          key: cabal-cache-${{ matrix.os }}-${{ matrix.ghc }}-${{ hashFiles('**/*.cabal') }}
-      - run: cabal new-build --only-dependencies
-      - run: cabal new-build
-      - run: cabal new-test --test-show-details=direct
+        run: nix build -L '.#devShells.x86_64-linux.default'