[skip ci] Save disk space on GitHub-hosted macOS runner

Author: kateinoigakukun

.github/scripts/build-matrix.rb

@@ -94,6 +94,7 @@
     "run_e2e_test": true,
     "build_hello_wasm": true,
     "clean_build_dir": true,
+    "free_disk_space": true,
     "only_swift_sdk": false,
   },
   {

.github/workflows/build-toolchain.yml

@@ -121,7 +121,7 @@ jobs:
     runs-on: ${{ matrix.agent_query }}
     steps:
       - name: Free disk space
-        if: ${{ matrix.free_disk_space }}
+        if: ${{ matrix.free_disk_space && !startsWith(matrix.build_os, 'macos-') }}
         run: |
           df -h
           sudo rm -rf /opt/hostedtoolcache
@@ -133,6 +133,18 @@ jobs:
           fi
           df -h
 
+      - name: Free disk space by removing unused Xcode
+        if: ${{ matrix.free_disk_space && startsWith(matrix.build_os, 'macos-') }}
+        run: |
+          IN_USE_XCODE=$(xcode-select -p)
+          echo "Removing all Xcode installations except $IN_USE_XCODE"
+          for xcode in /Applications/Xcode*.app; do
+            if [[ $IN_USE_XCODE != "$xcode"* ]]; then
+              echo "Removing $xcode"
+              rm -rf $xcode
+            fi
+          done
+
       - uses: actions/checkout@v4
         with:
           path: swiftwasm-build