FIX: Update deprecated GitHub Actions to latest versions

Updated deprecated actions across workflow files:

**Release Workflow:**
- actions/upload-artifact@v3 → @v4
- actions/download-artifact@v3 → @v4

**Build & Deploy Workflow:**
- actions/configure-pages@v3 → @v4
- actions/upload-pages-artifact@v2 → @V3
- actions/deploy-pages@v2 → @V3

This resolves the GitHub Actions deprecation warnings that were
causing deployment failures on the main branch.

Fixes the error: "This request has been automatically failed
because it uses a deprecated version of actions/upload-artifact: v3"

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

Co-Authored-By: Claude <[email protected]>

Author: pwt-cd

.github/workflows/build-deploy.yml

@@ -326,16 +326,16 @@ jobs:
           echo "${{ needs.build-documentation.outputs.build-timestamp }}" > ./pages-content/BUILD_TIME
 
       - name: Setup Pages
-        uses: actions/configure-pages@v3
+        uses: actions/configure-pages@v4
 
       - name: Upload to GitHub Pages
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v3
         with:
           path: ./pages-content
 
       - name: Deploy to GitHub Pages  
         id: deployment
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v3
 
       - name: Update deployment status
         run: |

.github/workflows/release.yml

@@ -354,7 +354,7 @@ jobs:
           ls -la "${PACKAGE_NAME}".{zip,tar.gz}
 
       - name: Upload release artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: boost-release-${{ steps.version-info.outputs.version }}
           path: |
@@ -377,7 +377,7 @@ jobs:
           fetch-depth: 0
 
       - name: Download release artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: boost-release-${{ needs.build-release.outputs.version }}
           path: ./release-artifacts