Chore: Update download-artifact and upload-artifact actions to v4

[petetronic]

Chore: GitHub announced that v3 of actions/upload-artifact and actions/download-artifact will be closing down and would start brownouts on November 14th. The change required is to simply move to v4 of these actions.

See:
https://github.blog/changelog/2024-11-05-notice-of-breaking-changes-for-github-actions/

.github/actions/build-vsix/action.yml

-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4

.github/actions/smoke-tests/action.yml

-      uses: actions/download-artifact@v3
+      uses: actions/download-artifact@v4

[eleanorjboyd]

Yes we are planning on doing this. I saw your PR regarding this problem: #24395. Any reason you closed it? We could iterate on that and merge this in to fix that problem. Thanks