CI templates rebuild Rust apps 3 times

Since the migration to one template to rule them all, all my Rust applications are now being built 3 times instead of one.

See for example

• 1st time: normal build https://gitlab.gnome.org/World/design/contrast/-/jobs/734093#L226
• 2nd time: https://gitlab.gnome.org/World/design/contrast/-/jobs/734093#L716
• 3rd time: running tests https://gitlab.gnome.org/World/design/contrast/-/jobs/734093#L1125

This ends up in a CI that takes way much longer and for some huge apps like Fractal, this takes forever.