Pass S3 secrets for nightly builds and fix windows build

Secrets need to be passed to reusable workflows either
by name or by `secrets: inherit` from the caller workflow.
The latter allows accessing all secrets in scope.

Windows build has a bug where the upload-nightly command is
not run from the correct working directory.

Closes #29614

Signed-off-by: Mukilan Thiyagarajan <me@mukilan.in>

.github/workflows/windows.yml

@@ -82,6 +82,7 @@ jobs:
           path: C:\\a\\servo\\servo\\target/release/msi/Servo.exe
       - name: Upload
         if: ${{ inputs.upload }}
+        working-directory: "C:\\a\\${{ github.event.repository.name }}\\${{ github.event.repository.name }}"
         run: python mach upload-nightly windows-msvc --secret-from-environment
         env:
           S3_UPLOAD_CREDENTIALS: ${{ secrets.S3_UPLOAD_CREDENTIALS }}