ovpn-dco: bump version to 0.2.20251017 and do not build for linux 6.18

[graysky2]

📦 Package Details

Maintainer: @zhaojh329
_{(You can find this by checking the history of the package Makefile.)}

Description:

Linux 6.18 has an in tree ovpn so restrict this to the 6.12 kernel.

🧪 Run Testing Details

• OpenWrt Version: SNAPSHOT
• OpenWrt Target/Subtarget:
• OpenWrt Device:

not run tested just build tested for x86/64-glibc

✅ Formalities

• I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

If your PR contains a patch:

• It can be applied using git am
• It has been refreshed to avoid offsets, fuzzes, etc., using

  make package/<your-package>/refresh V=s

• It is structured in a way that it is potentially upstreamable
  _{(e.g., subject line, commit description, etc.)
  We must try to upstream patches to reduce maintenance burden.}

[sanderpqr]

#27421 ?

[graysky2]

@sanderpqr - maybe? I did not test that PR.

[LGA1150]

@sanderpqr @graysky2
6.18 has the in-tree ovpn driver (drivers/net/ovpn), so we could mark this package as 6.12-only.