Bump external/libbtf from 69e0268 to 2de28d7

Bumps [external/libbtf](https://github.com/Alan-Jowett/libbtf) from `69e0268` to `2de28d7`.
- [Release notes](https://github.com/Alan-Jowett/libbtf/releases)
- [Commits](Alan-Jowett/libbtf@69e0268...2de28d7)

---
updated-dependencies:
- dependency-name: external/libbtf
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>