refactor CI stuff so it is simpler and better contained

.github/workflows/build.yml

@@ -0,0 +1,58 @@
+name: Build
+
+on: [push, pull_request]
+
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Compile on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, windows-latest, ubuntu-latest]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup MSVC environment
+        uses: ilammy/msvc-dev-cmd@v1
+        if: matrix.os == 'windows-latest'
+
+      - uses: mamba-org/setup-micromamba@v1
+        name: Setup Conda
+        with:
+            init-shell: bash
+            environment-file: environment.yml
+            environment-name: "wrench"
+            cache-environment: true
+            cache-downloads: true
+
+      - name: Create working directory
+        shell: bash -l {0}
+        run: |
+          mkdir build
+
+      - name: Run cmake
+        shell: bash -l {0}
+        working-directory: ./build
+        run: |
+          if [ "$RUNNER_OS" == "Windows" ]; then
+            export CC=cl.exe
+            export CXX=cl.exe
+          fi
+          cmake -G Ninja \
+            -DCMAKE_INSTALL_PREFIX=${CONDA_PREFIX} \
+            ..
+
+      - name: Build pdal_wrench
+        shell: bash -l {0}
+        working-directory: ./build
+        run: |
+          ninja
+          ninja install

environment.yml

@@ -0,0 +1,11 @@
+name: wrench
+channels:
+  - conda-forge
+dependencies:
+  - conda
+  - mamba
+  - compilers
+  - ninja
+  - cmake
+  - pdal
+