New issue by camj2 on void-packages repository

https://github.com/void-linux/void-packages/issues/50669

Description:
### Is this a new report?

Yes

### System Info

Void 6.1.77_1 aarch64-musl Unknown uptodate F

### Package(s) Affected

rpi-kernel-6.1.77_1

### Does a report exist for this bug with the project's home (upstream) and/or another distro?

_No response_

### Expected behaviour

`/etc/runit/core-services/08-sysctl.sh` loads rules from `/etc/sysctl.conf`.

### Actual behaviour

Some rules, such as `net.ipv6.conf.all.forwarding = 1`, fail to load at boot. Running `sysctl -p` manually loads them fine just though.

![sysctl](https://github.com/void-linux/void-packages/assets/139597610/058d6904-a273-48ae-8ac4-22131ad591e8)

### Steps to reproduce

1. Add `net.ipv6.conf.all.forwarding = 1` to `/etc/sysctl.conf`.
2. Reboot.
3. `sysctl -a | grep net.ipv6.conf.all.forwarding` shows the rule wasn't applied at boot.