Switch to self-hosted runners for macOS (#4511)

.github/workflows/macos.yml

@@ -7,38 +7,22 @@ jobs:
     strategy:
       matrix:
         platform:
-          - macos-12
+          - macos
         generator:
           - Ninja
         configuration:
           - Release
-    runs-on: ${{ matrix.platform }}
+    runs-on: [self-hosted, macOS]
     env:
       # The `build` action requires these variables.
       build_dir: .build
-      NUM_PROCESSORS: 2
+      NUM_PROCESSORS: 12
     steps:
       - name: checkout
         uses: actions/checkout@v3
       - name: install Ninja
         if: matrix.generator == 'Ninja'
         run: brew install ninja
-      - name: choose Python
-        uses: actions/setup-python@v3
-        with:
-          python-version: 3.9
-      - name: learn Python cache directory
-        id: pip-cache
-        run: |
-          sudo pip install --upgrade pip
-          echo "dir=$(pip cache dir)" >> $GITHUB_OUTPUT
-      - name: restore Python cache directory
-        uses: actions/cache@v2
-        with:
-            path: ${{ steps.pip-cache.outputs.dir }}
-            key: ${{ runner.os }}-${{ hashFiles('.github/workflows/nix.yml') }}
-      - name: install Conan
-        run: pip install wheel 'conan<2'
       - name: check environment
         run: |
           echo ${PATH} | tr ':' '\n'
@@ -46,19 +30,6 @@ jobs:
           conan --version
           cmake --version
           env
-      - name: configure Conan
-        run: |
-          conan profile new default --detect
-          conan profile update settings.compiler.cppstd=20 default
-      - name: learn Conan cache directory
-        id: conan-cache
-        run: |
-          echo "dir=$(conan config get storage.path)" >> $GITHUB_OUTPUT
-      - name: restore Conan cache directory
-        uses: actions/cache@v2
-        with:
-            path: ${{ steps.conan-cache.outputs.dir }}
-            key: ${{ hashFiles('~/.conan/profiles/default', 'conanfile.py', 'external/rocksdb/*', '.github/workflows/nix.yml') }}
       - name: build
         uses: ./.github/actions/build
         with: