Go 1.16 added the signal.NotifyContext helper utility. `installSignals` could be further inlined in a future iteration, if needed.
When reading the [function documentation](https://pkg.go.dev/os/signal#NotifyContext), it becomes clear that this is doing the exact same thing as the old code.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/10311
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: nachtjasmin <nachtjasmin@posteo.de>
Co-committed-by: nachtjasmin <nachtjasmin@posteo.de>
