fix: 🔧 update artifact actions from v3 to v4

- Updated actions/upload-artifact from v3 to v4
- Updated actions/download-artifact from v3 to v4
- Fixes deprecation warnings in GitHub Actions workflow

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: mikebronner

.github/workflows/build.yml

@@ -107,7 +107,7 @@ jobs:
         copy lsp-server\target\${{ matrix.target }}\release\${{ matrix.binary_name }} dist\
     
     - name: Upload artifact
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: ${{ matrix.artifact_name }}
         path: dist/${{ matrix.binary_name }}
@@ -122,7 +122,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Download all artifacts
-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4
       with:
         path: artifacts