fix: remove workspace-copy to preserve cargo target cache

workspace-copy: true changes GITHUB_WORKSPACE path, which invalidates
the oxc-project/setup-rust target directory cache and forces a full
Rust rebuild (6min → 18min regression).

Fix: keep workspace on C: drive, only put CARGO_HOME and RUSTUP_HOME
on the Dev Drive (matching rolldown's approach). Also re-add Defender
disable since Dev Drive without workspace-copy doesn't bypass Defender
for workspace files.

Author: fengmk2

.github/workflows/ci.yml

@@ -70,13 +70,19 @@ jobs:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
       - uses: ./.github/actions/clone
 
-      # Use Dev Drive with ReFS on Windows for faster I/O (bypasses Defender scanning automatically)
+      # Disable Windows Defender real-time scanning to speed up I/O-heavy builds (~30-50% faster)
+      - name: Disable Windows Defender
+        if: runner.os == 'Windows'
+        shell: powershell
+        run: Set-MpPreference -DisableRealtimeMonitoring $true
+
+      # Use Dev Drive with ReFS for CARGO_HOME/RUSTUP_HOME on Windows
+      # Only cargo/rustup dirs go on the Dev Drive (no workspace-copy) to preserve target dir cache
       - name: Setup Dev Drive
         uses: samypr100/setup-dev-drive@30f0f98ae5636b2b6501e181dfb3631b9974818d # v4.0.0
         if: runner.os == 'Windows'
         with:
-          workspace-copy: true
-          drive-size: 12GB
+          drive-size: 8GB
           drive-format: ReFS
           env-mapping: |
             CARGO_HOME,{{ DEV_DRIVE }}/.cargo
@@ -198,13 +204,18 @@ jobs:
       - name: Configure Git for access to vite-task
         run: git config --global url."https://x-access-token:${{ secrets.VITE_TASK_TOKEN }}@github.com/".insteadOf "ssh://git@github.com/"
 
-      # Use Dev Drive with ReFS on Windows for faster I/O (bypasses Defender scanning automatically)
+      # Disable Windows Defender real-time scanning to speed up I/O-heavy builds (~30-50% faster)
+      - name: Disable Windows Defender
+        if: runner.os == 'Windows'
+        shell: powershell
+        run: Set-MpPreference -DisableRealtimeMonitoring $true
+
+      # Use Dev Drive with ReFS for CARGO_HOME/RUSTUP_HOME on Windows
       - name: Setup Dev Drive
         uses: samypr100/setup-dev-drive@30f0f98ae5636b2b6501e181dfb3631b9974818d # v4.0.0
         if: runner.os == 'Windows'
         with:
-          workspace-copy: true
-          drive-size: 12GB
+          drive-size: 8GB
           drive-format: ReFS
           env-mapping: |
             CARGO_HOME,{{ DEV_DRIVE }}/.cargo