ci: Extend packaging pipeline to sign Windows binaries automatically

Split packaging on Windows into dedicated jobs that run with access to
an EV signing certificate.

Prior to commit 0929221ca3 (gitlab-ci: Simplify Windows packaging
pipeline, 2023-02-28, v3.26.0-rc5~3^2~3) we had separate packaging jobs,
but they did not run in release packaging pipelines.  Restore them, and
run them in both nightly and release packaging pipelines.